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WIGGLING 'LITE' IN GUEST MODE

Sonic Potions - Penrose Quantizer DIY Kit
MUFF WIGGLER Forum Index -> Music Tech DIY  
Author Sonic Potions - Penrose Quantizer DIY Kit
Comboy
Hello fellow wigglers!

I hope it is ok to post here.
I recently developed a quantizer with user selectable scales as a DIY kit for the eurorack format.



Notes can be selected with the duocolor LED buttons and it is either free running (no cable plugged into the trigger in jack) or externally triggered (cable attached). Whenever the output changes a trigger is generated.It uses a proper DAC for CV output, so no PWM is used.

More information is available on my website

and full kits are available in my shop

I hope you like it! razz
horstronic
applause applause applause
woodster
I think I'll be having me some of that SlayerBadger!
Adminius
This looks monster, Comboy!

I actually found the Penrose Quantizer on ModularGrid only yesterday and added it to my GearLust Rack.

Any plans to produce this as a completed module 'cause I'm decidedly dodgy at DIY?
Comboy
No plans for me so far to make a complete module, but I'm sure one of the trusted builders would be happy to build one for you for a good price. Maybe ask andre' from tubeOhm or someone else from this list:

http://forum.sonic-potions.com/discussion/258/trusted-builders

I thought there are quite a few ready made quantizers but very few DIY kits so I went with the kit wink
Coconuts
Will any shops in the U.S. have them?
Altitude909
Welcome Julian!

I can build these in the US for anyone that needs one.
horstronic
And I could build these for people in europe w00t
FetidEye
i just got mine in the mail.. thanks for the nice presents!!

btw: that small bottle with the wooden cap, where did you got it from?
my girlfriend wants to use such bottles for a food / oil project.
bartleby
received mine today - including some obscene candy. grin

don't know when i'll find the time to build this - my backlog is long enough. but i think i'll move this one up on the list...
FetidEye
aaannnd it works!!



fast build, because of the excellent manual.
calibration was fast too, maybe i'll redo it with a scope, but for now a multimeter worked fine.
The buttons are very beautiful!

1 point of attention: it would be very usefull to have an overview of all components at the beginning. (like a BOM)
In that way you can't mistake a 102 cap for a 104 cap because you will know to look out for it. (those text codes are so fucking small it hurts my eyes)

very cool solution for the pcb / panel mounting also!!

w00t
falafelbiels
That was quick!
beeedy
I would also be willing to build for people in the US if altitude becomes too busy! help
Ucture
I just build and tested the Penrose i ordered last week. There's 3 light buttons (G#, A#, B) that does not light but are working. I checked my soldering and it looks like everything is ok. I thought also to update the firmware but couldn't find the audio file to do it, on the site. Does anyone have the same issues? Any solutions or check i can do?
woodster
Did you make sure to follow instructions which way to put the button pins in ?
Ucture
I received an answer from Julian by mail. It's apparently a defect 10 Ohm resistance.
reodjectz
I like the look of this module. Could one of the people who picked it chime in on the panel quality? Is it hand made (like the befaco ones, I hope not) or nice and cleanly manufactured?

Really love the idea of the trigger out on pitch change, I wish the uscale had that.

If the panels are nice I'll be ordering.
spoor
reodjectz wrote:
Is it hand made (like the befaco ones, I hope not)

BTW - latest module I built from them (Even VCO) was very much improved, using aluminium PCB material. But still not as nice as others (grayscale, MI, MTM etc). I understand they're still looking to improve their panels.
reodjectz
spoor wrote:
reodjectz wrote:
Is it hand made (like the befaco ones, I hope not)

BTW - latest module I built from them (Even VCO) was very much improved, using aluminium PCB material. But still not as nice as others (grayscale, MI, MTM etc). I understand they're still looking to improve their panels.


Good to hear- I like their modules, but the panels are a huge turnoff. I did just order the sampling modulator kit... fingers crossed for a nice panel.
Altitude909
That looks like a metal photo panel like the MI (it was designed by the same guy)
euromorcego
looks wonderful.

So the selectable scales are not presets but one has to program the scales using the minikeyboard? And I am correct that there is no transpose or similar? Could the mini keys be used as a, well, mini keyboard, when nothing is plugged in? That would be a useful feature (have been looking for something like this).
tonewheels
I got my kit a couple of days ago. Panel is really nice. Seems to be an emerging wiggling practice to give toys with the kit. Nice. A packet of camel balls and a jar to keep your oil (been years since I've come across any oil, mind you).

Since I ordered it, my circumstances/requirements have changed so I'll either trade it or build it and trade it. Cool module though. Mightily impressed.
Comboy
FetidEye wrote:
btw: that small bottle with the wooden cap, where did you got it from?
my girlfriend wants to use such bottles for a food / oil project.


found them on alibaba wink
have a look for "Fimo bottle"
Lots of different varieties available.
Comboy
reodjectz wrote:
I like the look of this module. Could one of the people who picked it chime in on the panel quality? Is it hand made (like the befaco ones, I hope not) or nice and cleanly manufactured?


The panels are quality aluminum panels with sub anodized (is this the right term?)printing.
Similar to the Mutable panels.

Scratch and solvent proof.
I had to get samples from 5 companies until I found one with good quality wink
Comboy
euromorcego wrote:
looks wonderful.

So the selectable scales are not presets but one has to program the scales using the minikeyboard?


exactly.

euromorcego wrote:
And I am correct that there is no transpose or similar? Could the mini keys be used as a, well, mini keyboard, when nothing is plugged in? That would be a useful feature (have been looking for something like this).



Sorry, no transpose. About the mini keyboard use - I'm afraid there are no free pins on the microcontroller left an the CV in jack has no switch wired up to detect if a jack is plugged in.
The firmware could be changed to act as a small keyboard, but it would not work as a quantizer anymore :(
reodjectz
Comboy wrote:
reodjectz wrote:
I like the look of this module. Could one of the people who picked it chime in on the panel quality? Is it hand made (like the befaco ones, I hope not) or nice and cleanly manufactured?


The panels are quality aluminum panels with sub anodized (is this the right term?)printing.
Similar to the Mutable panels.

Scratch and solvent proof.
I had to get samples from 5 companies until I found one with good quality wink


Great to hear. I have my order in. BTW what other DIY Kits are in the works for eurorack?
Comboy
none at the moment.
But that doesn't mean there won't be any more wink
sammy123
Hi Comboy, do you have an ETA on panel/pcb or panel/pcb/chip sets being available? Thank you.
Comboy
over the next few days.
I first have to finish the BOM so you know which parts to get wink
spend the last days preparing a new LXR maiboard production since I noticed I'm running low on mainmborads wink
ClausF
Build without problems, great manual, great module!
Javier
Hi! I am going to adapt the Penrose Quantizer to my modular which uses banana cables. In order to do that I need to make my own panels, please where can I get the pdf to print the design and make the transfer to my panels? Is it going to be available? Then I'll be able to drill the holes in the exact place.
Comboy
here you go
http://www.sonic-potions.com/public/Penrose/PenrosePanelLayout.pdf

I'll prepare a GitHub repo over the next days with all the Layout and source code files, too.
xerxl
Since we're on the topic of modifying...
My diy skills are a bit rudimentary. Would it be reasonably easy to get it to run on +/- 15V?
Looks really nice Comboy!

Cheers
Comboy
shouldn't need much modifications.
+/- 12V are only used for the TL072 opamp that buffers the CV IO.
Those work nice up until +/- 18V

Maybe a bigger 5V regulator would be needed as at the moment it is using a 78L05 regulator:

which might get a little hot if it has to dissipate another 3V.

so maybe using a normal 7805 regulator, eventually with a heatsing would be better for 15V.
fuzzbass
My kit just arrived today. Great swag! Can't wait to build it.
fuzzbass
Someone was talking about transpose. Queue my little Arturia Beatstep, which has CV out. In "pads" mode, you can map the pads to notes, and corresponding voltages come out. If you have a unity gain 2 channel mixer (like say the little mixers on Manhattan Analog Manual Voltage Processor), you can use the Beatstep pads to transpose your quantized CV. Its a little more musically intelligible if you transpose before you quantize.
Javier
Thank you Comboy!!

By the way, my kit has just arrived!

Nice bottle!! Great juicy Camel Balls!! The panel looks really good, smooth and nice. Now I want to use it and I will try to make the holes bigger to fit the banana sockets.

Just one last question.... since I am not going to use the 4 audio jacks, please could you show me which lug carries the signal for each audio jack? Then I will make the connection to my banana sockets from there.
Comboy
Here is a picture showing the signals on the PCB.
Please note that the left and right jacks have a different orientation.



Blue: signals
Pink: GND
Yellow: Cable detect contact

The yellow marked lug could be a problem with banana. sad banana
It uses a contact on the 3.5mm jack to detect if a cable is inserted.
If no cable is in the jack, the lug has no contact and is pulled high by a pullup on the uC.
If a cable is present it has contact to GND and the signal is low.
This switches between free running and triggered operation.
Dogma
im looking for a quantizer and Ive narrowed it down to this and the Ustep. Can someone tell me major plus and minus of the 2? Im sure Im not the only one asking this question.
Javier
Thanks for the detailed info Comboy!

Ooops, all right, I will use the audio jack for the trigger input, this is also ok as I have a banana to audio jack converter module. I hope everything works fine!
Captain77
I think I'll purchase one too. very soon...
oscarthesquirrel
Got my kit a few weeks ago and got around to building it a few days back. Fairly straightforward build, although a little tight in some places (my chisel tip probably should have been swapped ar some points for a...err pointy tip).

I actually spent more time getting the panel to fit than anything. It really is vital to get the switch pots absolutely flush and the jack pots level. I found that the jack pots were slightly lower than the switches, meaning a slight downward gradient on the panel and 3 sticky (i.e. catching) note switches. A bit of bodging and repositioning later and everything is fine.

Calibration took a while - but I'm a noob when it comes to these things,and I eventually got there...but its working great and is wonderfully easy to use on the fly.

Camel Balls and bottle were a a nice bonus :-)
FetidEye
Dogma wrote:
im looking for a quantizer and Ive narrowed it down to this and the Uscale. Can someone tell me major plus and minus of the 2? Im sure Im not the only one asking this question.



penrose:
you can DIY this, for me this is a very good plus.
no menu's / hidden functions
clear interface, very playable

Uscale:
way more functions
less hp?
woodster
I think it's a fantastic quantiser, most definitely the best DIY one available!.
A few people I know seemed a little apprehensive regarding the 8bit chip (and hence the resolution).
However, once they've tried it, they have all been bowled over by the accuracy and sheer wigglability of it nanners
adnauseam
I'm really enjoying my Penrose quantizers.

I like changing the active notes as I wiggle.

I was dreaming the other day of a 2hp expander module with user writeable/selectable scales!

Then you could make chord progressions with the touch of a button.

Tuning it can be a bit finicky I find. I did mine by ear and recently tuned them again - this time I tuned both to the Quantized voltages of my Rene.

Great little design!
oscarthesquirrel
adnauseam wrote:


Tuning it can be a bit finicky I find. I did mine by ear and recently tuned them again - this time I tuned both to the Quantized voltages of my Rene.

Great little design!


I'm really glad I upgraded my multimeter and could measure frequency.....

The module is great for arpeggios..just feed a triangle wave into it via an attenuator to control octave range....and then adjust on the fly...

Excellent panel and interface design too
bookends
Anyone have an idea of approximate build time on this? (I know that depends on skill level but...)
oscarthesquirrel
bookends wrote:
Anyone have an idea of approximate build time on this? (I know that depends on skill level but...)


Took me about 3-4 hours , going slowly and carefully, with the odd tea break. Most time was spent in getting the panel flush and ensuring the buttons weren't sticking/catching.
mDang
I just order 3 of it ! 1 for me and others for friends wink
bookends
Built mine yesterday. Haven't had a chance to power it up yet but really enjoyed the build.

I soldered 1 pin each on the switches to hold them down and then finished soldering them once I had the panel on. Didn't have much of a problem with that. My clearance on the electrolytic caps is pretty tight so I might try to insulate them some with nail polish or silicon gel or something. Anyway looking forward to using this.
horstronic
Oh no, it's out of stock help
Any idea when you will have new kits?
Phoobooz
Also interested in when there will be more stock.
Raytracer
Phoobooz wrote:
Also interested in when there will be more stock.
+1
dot matrix madness
I would also be interested. Let's see if we get enough to justify a new batch.
loopook
Can anyone confirm if the module retains its settings after a power down?

If so I'd buy three smile
pld
Settings are saved 10 or 15 seconds after the last change.
cranleigh
Also interested in one if there is another run!
jgb
Will more of these be available soon? smile
ezod
Part way through the build! I'm waiting for a couple bits before I can complete it. The PCBs are very clearly labeled and Julian's instructions are great. The relatively small pads and solder mask aren't best friends with the solder I was using, but it didn't take long to get used to that.

One gotcha if you're sourcing your own parts: the 10K trimmer needs to be side-adjusted and have the triangular pin configuration (which may not be obvious if you just glance at the BOM parts). Bourns 3296Z-1-103LF seems correct, I didn't have any on hand, so that's one of the parts I'm waiting on. smile

I'm curious about the choice of 10-pin bus connectors in many DIY kits such as this one. If there were pads for a 16-pin connector, one could opt for either, and optionally jumper the 5V rail in place of the onboard regulator, which would presumably be easier on the power supply than yet another linear regulator. (Ideally it would actually have traces and jumper pins to support this, so that you could still include the 78L05 for completeness, e.g. if you wanted to sell it later on.)

A clean and easy DIY project! Looking forward to using it. Planning to demo a new sequencer with it soon, will shout out then. smile

Altitude909
I have a couple of new assembled and calibrated ones for sale if anyone's interested.
audiohawk
Great project for a n00b like me!
Well documented and easy to build.
Finished mine in one day. And it works!!! Now it needs calibration...
Recomended for starting DIY adventures with confidence.
Thanks!
bookends
finally powered mine up yesterday and i absolutely love it
Dogma
I thought this was going to be a permanent thing seriously, i just don't get it seriously, i just don't get it
Hell yeah another run - there are hardly any quantizers - relative to there importance.....
Now where? I dont like my quantimator that much - disting?
CeeJay
There will be a new batch of Penrose very soon (Julian from Sonic Potions told on Twitter some days ago).
sinemod
Where was i all this time !!!
That look dead right to me.
I just bought a UScale but i will buy this in a heart beat !!!!
sumdumguy
totally looking forward to another batch of these
SmartBits
I (finally) finished building it and it works, yay! Still need to calibrate is but lights go on and no magic smoke, so that's promising. This was only my second Eurorack kit I've built (the 4ms RCD and expander being the other), but i only needed a hand at some points. Overall an easy and very well documented build, thanks comboy (and Fetideye for support Guinness ftw! )!

Remarks from a n00bs perspective:

PCB: sometimes the solder couldn't quite stick to the PCB. Setting the iron to higher improved that, but still I had a few spots where I had quite a bit of trouble soldering.

Maybe there could be a remark in the instructions at the point where you have to solder the electrolytic capacitors that they have to be as close to the PCB as possible. Since space between the PCB's is limited there is a warning (when putting the two PCB's have to be put together) that the electrolytic capacitors shouldn't touch the jack lugs. But by then you've already soldered them. Luckely, by snipping off the jack lugs really close to the PCB I didn't have a problem, but others might not be.

Jacks: The green/red markings on the jack connectors was a bit of a thing for me. As I'm colourblind (and I believe something like 8% of the male population is) I couldn't destinguish between red and green markings on the side of the connectors, so i needed some assistance with that. Maybe if you just mark only one side, that would have been a solution for me.
timpecter
I'm also in for one (or two) of these when they become available again.
Adminius
I'm gonna get over my aversion to Euro DIY and order one of these babies just as soon as they become available.

I'd better dig out my old solderin' iron.
SmartBits
SmartBits wrote:
Jacks: The green/red markings on the jack connectors was a bit of a thing for me.

Where I said jacks, I meant the push buttons ofcourse... d'oh!
Jarno
+1, the orientation of the switches was a bit of a headscratcher for me (especially as my green-red vision is not great)

Also, I heard some comments about soldering. As the PCB has a ground plane, the solder connections to ground need a tad more heat than the other solder connections. The thermal reliefs used could be a bit thinner.
SmartBits
I just saw that there's also a video for the calibration procedure:



Handy!
Comboy
I was just waiting for new front panels to be manufactured.
But the "ready in 2 weeks" turned out to be a "ready after 5-6 weeks" Dead Banana

Yesterday I finally got another batch of panels! So today I will have to finish the quality check and sort the rest of the kits and they will be available again in the shop tomorrow or monday It's peanut butter jelly time!
Comboy
Quantizers are back in stock at the shop
https://www.sonic-potions.com/shop/index.php?route=product/category&pa th=63

VAT will automatically be removed once you enter an address outside of the EU.
jgb
Ordered two! smile
sonicwarrior
Comboy wrote:
Quantizers are back in stock at the shop
https://www.sonic-potions.com/shop/index.php?route=product/category&pa th=63

Does the PCB include the chip? Else this option doesn't make much sense IMHO.
Comboy
you mean the atmega? No, but the .hex file to flash it yourself is available on github: https://github.com/SonicPotions/Penrose/raw/master/bin/FirmwareAndBoot loader.hex

I could add a chip, but in general flashing them is very easy and a good avr programmer is only about 5€.
sonicwarrior
Hmmm, too much hassle, I think I'll get a kit instead. Too lazy to look for the parts anyway. hihi
n0rd
Could you please clarify...

Does the kit come with a ATMEGA168-P?
If so, is the ATMEGA168A-P pre-programmed?
If it is not pre-programmed, can it be programmed whilst in the module?

Thanks,
Steve
Comboy
the full kit comes with everything you need to build the module.
all parts, frontpanel, PCB, ribbon cable, pre-programmed atmega (with bootloader for later updates or custom firmwares)

sonicwarrior was refering to the PCB only offer for people who want to self source their parts.
n0rd
Comboy wrote:
the full kit comes with everything you need to build the module.
all parts, frontpanel, PCB, ribbon cable, pre-programmed atmega (with bootloader for later updates or custom firmwares)

thumbs up
Silicium
There must be a arp implemented in the firmware!
Reality Checkpoint
Steve @Thonk is getting some of these in soon for us in the UK.
FetidEye
i have a question:
my settings won't save anymore.. they used to, but now i get the same setting no matter what i previously did : three top buttons are ON, rest OFF.

checked the connections / solderpoints. nothing looks weird... weird

anyone got a clue?
tweakfilter
can someone tell me if it quantizes bipolar signals?
LowOver
just ordered and payed already Guinness ftw!
Comboy
tweakfilter wrote:
can someone tell me if it quantizes bipolar signals?

No. It's only unipolar 0-10V
Monobass
Now stocking this module on Thonk!

http://www.thonk.co.uk/shop/penrose/

dot matrix madness
Got mine yesterday. Very fast dispatch thumbs up
Anyhow I have to finish my T914 fixed filter bank first. So the quantizer will be next. In the meantime two question:
Since the input CV range is in between 0 and 10V, is it possible to feed in signals from a noise source (e.g. Doepfer A-118 or MFOS Cornucopia) directly, or is a sample & hold or rectifier required to ensure positive voltages?
Which modules (besides modulation sequencers) do you use to feed the quantizer?
Comboy
the input is completely protected. Negative voltages are ignored and result in a 0V output. A sample and hold is already included in the quantizer via the external trigger input.

It also works great with tides or the dual function generator. wink
LowOver
aaaand arrrrived hyper wil build this this weekend.....
comes very fast , like that !!! SlayerBadger!
oscarthesquirrel
Just built my 2nd one...works great (as expected)! Now to build the third next weekend!!!

Question: In this 2nd kit, Julian included a 1K (from memory..could have been another value...) on a separate piece of paper with a note to replace one of the 100K resistors (R21 I think).

Is this a recommended retro-fit for the first quantiser I built 6 months ago ?
LowOver
got some time last saturday , easy build up ! works as suspected....
to Comboy : GOOD JOB we're not worthy
a100user
First PCB done last night, plan is to complete and test this evening.
Comboy
oscarthesquirrel wrote:
Just built my 2nd one...works great (as expected)! Now to build the third next weekend!!!

Question: In this 2nd kit, Julian included a 1K (from memory..could have been another value...) on a separate piece of paper with a note to replace one of the 100K resistors (R21 I think).

Is this a recommended retro-fit for the first quantiser I built 6 months ago ?


it affects the trigger out voltage.
with the old resistor value the trigger out only reaches ~2.5V
the new 1k resistor raises it to ~4.8V

I have no module that has trouble with the lower trigger out voltage, but for some picky modules it may be needed.
woodster
Interesting, I might mod mine.
Is it definitely R21 ?
a100user
All done and calibrated. Nice straightforward build.

Paired with my Korg SQ1 for a final test last night, does exactly what it says it does.

Thanks for a great project.
oscarthesquirrel
woodster wrote:
Interesting, I might mod mine.
Is it definitely R21 ?


I still have 1 kit to build at home..will check after work tonight and let you know hihi
oscarthesquirrel
woodster wrote:
Interesting, I might mod mine.
Is it definitely R21 ?


Replace the 1K resistor at R21 with 10R
woodster
oscarthesquirrel wrote:
woodster wrote:
Interesting, I might mod mine.
Is it definitely R21 ?


Replace the 1K resistor at R21 with 10R


thumbs up many thanks for confirming
sonicwarrior
So R21 has to be reduced from 100K to 10R? That is quite a difference. hmmm.....
Comboy
1k to 10 ohm.

This is due to a fault on my side :-.
The LED was added last and with the 2 board layout I did not notice (and none of the beta testers) that it forms a voltage divider with the 1k output resistor for the gate signal. sad banana

This brings down the gate voltage to ~2.8V
By changing the output resistor the gate voltage is raised to 4.8 - 4.9V again.

An alternative would be to raise the 220 ohm resistor of the LED to some kOhm and use an ultra bright LED.

the 10 ohm solution messes a bit with the output impedance, but for a gate its non crititcal I think and since it is also buffered by an opamp the output is still protected.

The layout bug will be fixed on the next batch of PCBs
Silesius
Hi, I've got a question about calibration; in the build guide it is said it's more accurate to use a vco+frequency counter for calibration than a multimeter. I've been calibrating mine with one of my vco's and an O'Tool. But then I tried with another vco and it didn't work the same way, because that other oscillator wasn't calibrated exactly equal to the first.
So I'm not sure about how accurate this method is, because it assumes you have perfectly 1v/oct calibrated oscillators. What happens if your vco's are not so perfect? I am asking this because I think I'm going to try with the multimeter route, because after a few tries with different vco's I am no longer sure where the mistake is, in the quantizer or in the vco's calibration.
Any ideas about this?
Jovenja
Hi, I built mine a few days ago but now I'm having some troubles with the calibration. I tried it with the "vco+frequency counter" method.

MidiKeyboard -> Midi2CV-Interface -> Penrose in
Penrose out -> MFB Kraftzwerg -> Kraftzwerg out -> Ableton/FrequencyCounter

I started with C2 and tuned the MFB accordingly. Played C3 and adjusted the trimmer of the quantizer. Played C2 again adjusted the MFB, repeated these steps some times until the tuning was kept perfectly.

Then I played C4 and things got strange. The frequency oscillated around C5, sounding somehow distorted. After 2 seconds the frequency "slid" down and finally hit C4 hmmm..... I changed to C3 again - perfect, played C4 - perfect.
Played C2 and C3 sometimes - perfect. Played C4 … same effect than the first time.

I also connected the Turing sequencer to the Penrose in and had the same effect. Everything is fine as long as I keep scale low. As soon as I raise the scale, the quantizer needs some time "to find the correct frequency" …

I checked the solder connections several times - everything "looks" fine. Any ideas, what could be wrong?

sorry for my crude english - it's even hard to explain this in german hihi
oscarthesquirrel
Silesius wrote:
Hi, I've got a question about calibration; in the build guide it is said it's more accurate to use a vco+frequency counter for calibration than a multimeter. I've been calibrating mine with one of my vco's and an O'Tool. But then I tried with another vco and it didn't work the same way, because that other oscillator wasn't calibrated exactly equal to the first.
So I'm not sure about how accurate this method is, because it assumes you have perfectly 1v/oct calibrated oscillators. What happens if your vco's are not so perfect? I am asking this because I think I'm going to try with the multimeter route, because after a few tries with different vco's I am no longer sure where the mistake is, in the quantizer or in the vco's calibration.
Any ideas about this?


I've built and calibrated 3 units. My VCO's are Doepfer A-111 High End, so they do track pretty damn accurately. I ended up using the voltage method rather than the frequency method - was quicker and easier for me even though my multimeter does have a frequency counter. Took me about 20 minutes going back and forth between C2, C3 and C4 . Above this I found if I changed C4 to C5 and adjusted, it threw out the wider range of C2-C4 very slightly.
Michiel
I've built and calibrated mine. All pretty straightforward - just a bit of tinkering to prevent the capacitors from touching the jacks. Would indeed be good to mention this in the build docs at the appropriate stage - not just in the troubleshooting section.

I did the calibration using the frequency measurement mode on the O'Tool with a number of different vco's (ST0, A-110, Disting Mode 4c, Braids). Can't say the process converges if I calibrate over multiple octaves 100-200-400-800-1600 Hz. By the time I get to 1600, I'm usually about 50-80 Hz off.

In the end I settled on something in between - good in the middle, a little off below and above. I get just over 5 octaves using Pressure Points to dial through (32.3, 65.0, 130.0, 259.3, 517.4, 1044.1, 2131.8 Hz). Is this about what's expected. The calibration procedure doesn't really give a clue what I should aim for.
mskala
K'ung Fu-tzu wrote:
The man who plays one pitch-pipe knows what note he is playing. The man with two pitch-pipes is never sure.


If your oscillators do not agree with each other, then it's too much to expect your quantizer to agree with all of them. Even different octaves on the same oscillator may not agree with each other if the oscillator doesn't track well, and a quantizer that has only one trimmer may not be able to match more than one interval on one oscillator.

Imagine the pitches as points plotted on a graph: if they do not line up in a straight line (poor tracking) then there is no amount of carefully laying a ruler on the graph (quantizer calibration) that will necessarily get it to line up perfectly with more than two points, and this is true regardless of whether the ruler is perfectly straight or only close. The only way to hit more than two notes perfectly on an imperfect oscillator would be to get a quantizer capable of more than one calibration adjustment.
Michiel
mskala wrote:
If your oscillators do not agree with each other, then it's too much to expect your quantizer to agree with all of them.


I realised that, but I certainly expect the digital oscillators (disting, braids) to track well over a fair number of octaves - which is exactly why I used them. Started off using the analogue VCO's but quickly realised that using a digital source would remove one degree of uncertainty from the calibration process, so opted for those.

The question remains therefore... what should we expect. There is no spec on this and I am just curious.
mskala
I don't know what you should expect from your oscillators. I calibrated my Penrose to a Z3000's internal frequency counter, using 1000Hz and 4000Hz if I remember correctly - that is, adjusting it to match both those to the 1Hz displayed precision of the counter. It matches my other Z3000 (after both are warmed up for a half hour) to within about +-3Hz on those notes, and other notes in the audio range on either oscillator to about +-10Hz, until the oscillator starts to go flat above about 7000Hz. These numbers are comparable to the specified uncertainty of the Z3000 frequency counter, so without getting better test equipment, I think it's about the best I can hope for.

If you are seeing an 80Hz error at 1600Hz when 100 and 800 are spot on, then I think your oscillator is mistracking.
Michiel
mskala wrote:
If you are seeing an 80Hz error at 1600Hz when 100 and 800 are spot on, then I think your oscillator is mistracking.


Thanks. I'll investigate further.
glennfin
Just ordered one. Can't find it on Modular Grid to add to my rack though.. hmmm.....
woodster
glennfin wrote:
Just ordered one. Can't find it on Modular Grid to add to my rack though.. hmmm.....


It's there alright -

https://www.modulargrid.net/e/sonic-potions-penrose-quantizer
mskala
ModularGrid's search does not show DIY modules by default. You must specify that under "Build type."
glennfin
Thank you..... didn't know that... although the Thonk Turing machine kits are in there


mskala wrote:
ModularGrid's search does not show DIY modules by default. You must specify that under "Build type."
mskala
glennfin wrote:
Thank you..... didn't know that... although the Thonk Turing machine kits are in there


They don't have the DIY tag, so it returns them in the search for assembled modules. This DIY/assembled thing is a relatively recent addition, so it's quite likely nobody has gone back and tagged older modules for it.
glennfin
Thanks...... that helped me discover the grayscale all-in-one panel for the 3 Turing Machine modules which I also just ordered. Money is flying out the door!! eek!

mskala wrote:
glennfin wrote:
Thank you..... didn't know that... although the Thonk Turing machine kits are in there


They don't have the DIY tag, so it returns them in the search for assembled modules. This DIY/assembled thing is a relatively recent addition, so it's quite likely nobody has gone back and tagged older modules for it.
glennfin
Received my kit yesterday, Started building it today and realized ALL the resistors are missing from the kit. seriously, i just don't get it That sucks. I'm pretty sure I have all the common resistor values but not that side mount 10k trim pot. very frustrating
n0rd
What are the changes from v0.3 and v0.4 PCB? Does the v0.4 PCB still require the R21 resistor change? (The Assembly Guide, BOM and Schematic on the Sonic Potions site still all show v0.3).
sromanel
Does anyone know where to find the buttons? They're out of stock at TME
bensaddiction
This looks fantastic,

I'm just curious to hear peoples opinions on how easy it has been to calibrate?
oscarthesquirrel
bensaddiction wrote:
This looks fantastic,

I'm just curious to hear peoples opinions on how easy it has been to calibrate?


I've built three and they are very straightforward - helps to have a DMM and/or frequency counter though....and patience...I'm a slower worker, so I take it steady and takes me 30-40 mins..could do quicker but what's the point ?
bensaddiction
Ok cool, so it can be done via a multimeter & doesn't necessarily require a scope?

The YouTube video used one of those inexpensive pocket scopes. I might end up getting one but it would be great to be able to build it without one
sammy123
I used a multimeter without any issues. It seems accurate enough.
bensaddiction
Thanks sammy123! I'll have to pull the trigger on a kit from Thonk
nebula 80
Just finished my Penrose build. Everything seems to work.
Except 4 buttons don't light up.

I resoldered already the buttons. Nothing has changed.

Any ideas on what and how to fix this issue?

Daniel
phosfiend
Hmm, my three bottom buttons don't light up either, was about to resolder them too. The buttons work for selecting notes however, just no visual feedback.

Also, the quantizer seems to have a lot of problems deciding what notes to select. It spends more time oscillating between two notes (with the gate output high) than staying on one... I'll look over my build, but pretty disappointed with this one so far.
phosfiend
OK, tried a few different voltage sources and the 'can't decide a note' problem is much better with other CVs.

Also, looks like my trigger input isn't working. Upon inserting a cable in the Trig In, the whole thing locks up and all the LEDs dim a little, looks like I have some hunting to do - any tips?
phosfiend
Got a prompt response from Julian, he's pointing me in the right direction smile
bobbcorr
SmartBits wrote:
I just saw that there's also a video for the calibration procedure:



Handy!


Very handy! BTW - what oscillator are you using there?
BugBrand
Made this a while back.. but didn't get around to posting::







Wasn't *too* complex a mod -- I was able to get a PCB panel tacked on to one of my proto PCB orders.
I added a mounting hole above the switches (there's a captive bolt on the proper panel)
Normalisation of the Trig socket was added with a switch - the regular socket is actually sensing if a MONO plug is inserted (ring to ground).
A bit tight with bananas - used spacers to make things right - drilled holes on PCB for 3 of them, but traces didn't allow for the Input so there I used a shorter banana.
Had to mount one IC (U2, I think) upside down / underneath - with pins bent upwards - for clearance..
And whacked on 7812/7912 for regulation down to +/-12V [funny, 'cos I looked over the schems and thought it may work fine direct from +/-15V but something was acting weird, so...]
BugBrand
Here are the board files (in the spirit of open-source).

eagle board + gerbers as a zip.
(this is, of course, frac sized - 1.5 x 5.25")
icenine
Did you eventually figure out what the challenge was?

phosfiend wrote:
Got a prompt response from Julian, he's pointing me in the right direction smile
icenine
Hopefully my question isn't too basic or obvious, but I've noticed quite a few DIY builds where the panel was essentially a PCB with no traces. Is this primarily a decision based on convenience because you already had a PCB order to place, or are there other advantages to this approach over acrylic or aluminum?

BugBrand wrote:
Made this a while back.. but didn't get around to posting::







Wasn't *too* complex a mod -- I was able to get a PCB panel tacked on to one of my proto PCB orders.
I added a mounting hole above the switches (there's a captive bolt on the proper panel)
Normalisation of the Trig socket was added with a switch - the regular socket is actually sensing if a MONO plug is inserted (ring to ground).
A bit tight with bananas - used spacers to make things right - drilled holes on PCB for 3 of them, but traces didn't allow for the Input so there I used a shorter banana.
Had to mount one IC (U2, I think) upside down / underneath - with pins bent upwards - for clearance..
And whacked on 7812/7912 for regulation down to +/-12V [funny, 'cos I looked over the schems and thought it may work fine direct from +/-15V but something was acting weird, so...]
BugBrand
Ease & aesthetics mainly - but then I'm a regular producer.. it may not be viable for most DIY builders.
Especially useful for prototype/one-offs like this where I can just add this on the edge of a large proto PCB order - means the panel is pretty PRO but costs me virtually nothing.
atte
Sorry if this has been asked before. Will the Penrose remember it's settings on power down+up?
n0rd
atte wrote:
Sorry if this has been asked before. Will the Penrose remember it's settings on power down+up?

Quote from Penrose Manual

"The module is equipped with an autosave feature. The selected notes are automatically saved to non volatile memory about 15 seconds after the last changes are made. This ensures that the module will always be in the same state after startup as it was before powering down your system."
atte
Great, thanks. Sorry I missed that d'oh!
antf4rm
I would love a pcb+panel set. Sounds like a great project and I'm in need of a quantizer. wink
antf4rm
So I've just purchased the panel and pcb set. How do I go about getting a programmed atmega?
sammy123
It's pretty easy to load the code if you have a programmer and avr studio, which is free.
xonetacular
restock on kits any time soon?
frankaponte
fun, straight forward build! definitely need a second one grin

nicely done, comboy!
atte
Yeah, I think I'm gonna grab two when they restock w00t
antf4rm
OK since i did not get the kit, i'm going to have to learn some AVR stuff. This is the first time i will attempt to dump a hex file onto an atmega. i have ordered a USBtinyISP, downloaded the files from github, installed AVRstudio5.0.
I have flashed other chips before like an stm32f and a teensy. I assume it's a similar process. any tips or things to look out for? better software?

Also which file do i use? FirmwareAndBootloader.hex??

Figured it wouldn't hurt to gather some info while waiting for the USBtinyISP and a mouser order to arrive.

PWM
I'd like one of these, if you restock.
sammy123
I set the fuses according to the github directions and then on the "memories" tab there are two sections to load a file; "flash" and "eeprom".  I loaded the quantizer.hex file to the flash section and it loaded.  Simple as that. Good luck.
atte
PWM wrote:
I'd like one of these, if you restock.


They are in stock at thanks and at sonic potions...
atte
2x post
antf4rm
sammy123 wrote:
I set the fuses according to the github directions and then on the "memories" tab there are two sections to load a file; "flash" and "eeprom".  I loaded the quantizer.hex file to the flash section and it loaded.  Simple as that. Good luck.


I'm not seeing where the instructions for setting the fuses is given.?

edit: i see now the .txt file in the bootloader folder
sammy123
Try the bootloader readme.

https://github.com/SonicPotions/Penrose/tree/master/Bootloader
PWM
atte wrote:
They are in stock at thanks and at sonic potions...



Thanks! I'll go there right now.
atte
I'm building a Penrose now. Noticed r21 is still 1k. I'm planing on replacing it with 10r, guess that should be problem free.

Any plans on updating kits + build manual?
n0rd
atte wrote:
I'm building a Penrose now. Noticed r21 is still 1k. I'm planing on replacing it with 10r, guess that should be problem free.

Any plans on updating kits + build manual?

I think the 10R mod is only required for older PCB's and not for the latest (v4?) PCB.
atte
Sounds strange to me that this could be a pcb only fix. Can anyone confirm this for sure?
n0rd
Found this at Sonic Potions forum:

"starting with version 0.4 the resistor change is not neccessary anymore."
atte
Ok, thanks. My pcb is 0.4 so I should be home free w00t
crc
my penrose suddently doesn't remember the previous settings after powerdown. it always boots in one scale i put there months ago. it worked perfectly before. any ideas what could cause this?
atte
I have finished my penrose, and while calibrating it, it strikes me as behaving odd, at least not what I'd expect. Here are a few videos, hope they play ok on your end. I'd really appreciate if someone would care to dig in and help me out...

Modules used: doepfer a-110 (vco), doepfer a-147 (lfo), qu-bit nanorand (clock), ladik c-040 (env) + BeatStepPro.

Video 1
Here I'm triggering octaves (C) straight from BSP to the osc. Just for reference. I realize that the tracking is a bit off, I think it's the doepfer, I measured the 1v/oct from the BSP with my meter and it's actually a bit flat in the higher registers (something like 5.98V instead of 6V)

Video 2
Again without the penrose, a chromatic scale (with mistakes in my playing) over the full range of the BSP. Just for reference.

Video 3
Now the penrose is between the 1v/oct out of the BSP and the 1v/oct in on the osc. Penrose have only one note in scale: C. Strange things happen:
1) The middle octaves doesn't change on C but on C#
2) The middle C (the one I goes back to half way up) confuses the penrose (it's LED is flashing like mad), seems like it can't decide which note to choose, so it does a very fast octave switch.

Video 4
Here all notes are enabled on the penrose. I'm playing C in all octaves on the BSP, but in the middle range penrose detects it as C# and in the high range it thinks it's D...

Video 5
Here the lfo (slow saw) is driving the penrose. First everything looks fine, the LED is flashing on new note detection. Then I connect the clock from nanorand to the trigger input of the penrose. The gate out from penrose is send to the ladik env, which has it's LED flash when penrose gets a trigger. Hmmm, I would expect the gate out to be send only when there was a new note (when penrose LED flashes), this is simply relaying the trigger input. Then I pull the trigger in, notice that nothing is send out through penrose gate out, I'd expect a trigger/gate on a new note detection.

So something seems to be off here. Any ideas where to start looking?
Brad
...so I have completed the first of the two PCBs and when i check it, I am getting a a short between the +12 and ground pins on the power connector..

Normally this is a bad thing... but I have not spotted any soldering errors yet.

By any chance, is this normal (as designed) on the Penrose?
atte
Basically I'm pretty stupid, but that can't be right. Although my build has problems (see above) I (amongst other things) checked just that, and had not continuity between either - 12v, +12 v and ground. I would be very surprised if that wouldn't be a flaw....
Heavy Metal Kid
Great module, easy build! Now I'm just pondering the mystery of the reasoning behind designing the front panel with the scale going downwards. seriously, i just don't get it hihi
Brad
Quote:
I (amongst other things) checked just that, and had not continuity between either - 12v, +12 v and ground. I would be very surprised if that wouldn't be a flaw....


Kind of what I figured... since I have not found anything else yet. I guess my next step is to unsolder the power connector. I used a shrouded header in place of the open pin array that the kit came.

Thanks for the info.
Brad
Quote:
next step is to unsolder the power connector.


That wasn't fun.

I think I found my problem - diode D1 ( 1n5819 ) is reading current in both directions which I know is not right.

Anyone out there know if I can substitute a 1n4001 or 1n4148 since those are the only spares I have right now?
CeeJay
Quote:
That wasn't fun.

I think I found my problem - diode D1 ( 1n5819 ) is reading current in both directions which I know is not right.

Anyone out there know if I can substitute a 1n4001 or 1n4148 since those are the only spares I have right now?


Why do you think diode D1 is causing the short? Did you measured the diode in circuit or after removing from the PCB? Is the short gone without D1?
atte
Could anyone please on if the behavior I'm getting in the above example videos is normal or not seriously, i just don't get it
Brad
Quote:
I think I found my problem


Apparently wasn't the diode. Finally spotted a tiny solder bridge on the pins of C13 and that fixing that cleared up the short.

Isn't DIY fun?
antf4rm
Just finished this build. Calibrated and working as expected. Hooray! I did not have the full kit so this was a challenging build in a few ways. I've never dumped a hex to a pic before so i had to buy a USBtinyISP and have a programmer friend help me with AVRdude. It is nice to learn some new things along the way.

So happy it fired up on the first try. applause



Maybe these strings of cammand line will help some others?

avrdude -p m168 -c usbtiny -U lfuse:w:0xff:m -U hfuse:w:0xd4:m -U efuse:w:0x02:m

avrdude -p m168 -c usbtiny -U flash:w:FirmwareAndBootloader.hex:i

avrdude -p m168 -c usbtiny -U lock:w:0x0F:m
PWM
Nice switches! Where did you got them?
n0rd
@atte

Answered some of your questions at Sonic Potions Thread.
Regarding "LED is flashing like mad" see thread Penrose Erratic Quantization also at Sonic Potions.

Steve
antf4rm
PWM wrote:
Nice switches! Where did you got them?


here is the link to the switches i purchased. not ez to find.

http://www.tme.eu/en/details/pb6149l-13-102/microswitches-tact-pcb/hig hly/
sonicwarrior
Just finished my Penrose and did a quick test without anything connected. One LED button is red though and can't be turned off. The others are green and can be turned off. hmmm.....
Too tired currently for any further tests.
woodster
that's exactly as it should be sirsonic thumbs up
atte
... Except it should be possible to turn buttons off...
FadingCanvas
I have been building a Penrose. I feel like a fool, but I can't get it working properly:

  • Note on/off LEDs work
  • A CV in doesn't do anything
  • The 4 highest notes change the pitch when turned on/off
  • When one of the other 8 notes is turned on, the pitch turns to the same very high tone
  • The trimmer does not seem to influence the pitch

Checked:

  • I'm sure the big capacitors aren't touching anything, clipped everything close by
  • Can't find solder bridges
  • Diodes have correct orientation, current flows one way
  • IC's have correct orientation
  • Checked schematic, it seems that row3 is only working ? But now what ? Paths of rows 1-3 from Atmega to other board all seem ok
  • Checked all resistors with a multimeter. Here's when things get strange, the 100k resistors measure this:

r7 99k
r20 100k
r2 51k
r9 51k
r14 104k
r15 99k

Checked and double checked resistance and color coding. How can this be ? Please assist, any ideas ? help
sonicwarrior
atte wrote:
... Except it should be possible to turn buttons off...

It is possible, just not with the currently played note button. Just tested it with an offset voltage and the red LED is moving around and the button can be turned off after it's green again.
I find this behavior a bit strange but I guess it's normal?
PWM
antf4rm wrote:
PWM wrote:
Nice switches! Where did you got them?


here is the link to the switches i purchased. not ez to find.

http://www.tme.eu/en/details/pb6149l-13-102/microswitches-tact-pcb/hig hly/


Thank you!
mg73
I calibrated my Penrose and it jumps good between octaves
but the 12 notes in every octave is a bit off, some almost 20ct
and it´s the same in every octave.
Is it not more exact or is something wrong with mine?

Maybe the firmware needs update but haven´t
found it anywhere.

Emailed Sonic Portions several times with no answer.
woodster
How are you calibrating and what are you using for measuring ?
I don't have a frequency counter, but a friend helped me calibrate mine using his.
There were a few little cents here and there which were wavering about, but nothing like 20 cents on mine, not that I remember anyway.
Does it make what your quantising sound off ?
mg73
I used a frequency counter and a voltage meter.

Yes for some sequences its annoying.
mskala
That may be the best accuracy you can expect. From the schematic, it's an MCP4801 8-bit DAC behind the CV output. With an output range of 0-10V, covering 12000 cents of musical range at V/oct, the 256 possible output values will be 46.9 cents apart. Most likely (I haven't checked the source code for the firmware) it's designed to use exactly one DAC step per quarter-tone, 240 over the entire range, so that the DAC steps are 50 cents apart and then the result will be as good as the linearity of the DAC. But the specs for the DAC would still allow individual steps to be off by 20 cents in such a design.
OlyNoCo
I just completed my kit. Had a difficult time getting the buttons to fit, and then some of them were sticking down, though I think that's under control.

I've calibrated it and it seems to track fairly well.

But... after about a minute, it just shuts off! I put my finger to the voltage regulator and it was hot. (Maybe that's normal?) I've been looking for shorts or other issues... anyone have an idea what would cause this to happen?
clusterchord
mskala wrote:
That may be the best accuracy you can expect. From the schematic, it's an MCP4801 8-bit DAC behind the CV output. With an output range of 0-10V, covering 12000 cents of musical range at V/oct, the 256 possible output values will be 46.9 cents apart. Most likely (I haven't checked the source code for the firmware) it's designed to use exactly one DAC step per quarter-tone, 240 over the entire range, so that the DAC steps are 50 cents apart and then the result will be as good as the linearity of the DAC. But the specs for the DAC would still allow individual steps to be off by 20 cents in such a design.


crap.. i am really interested in this module, love the ability to change the modes i.e. notes that play on-the-fly, and the visual confirmation. was considering having one built..

but i need accuracy better than what you describe. 20 cents is a humongous error. overall, reading thru bthe thread, seems jury is still out on accuracy of this thing in real world situation i.e. performing live etc..


can't there be a better version of this, even if costed more ? , like 16bit.. or 24bit DAC.. they are cheap as chips nowadays..
atte
I'm pretty sensitive to out of tune errors, and haven't found anything wrong with my Penrose. I'm planing on getting another...
mskala
The chip's specified worst-case error is a lot bigger than its specified "typical" error, so it's quite possible that if you swapped in other DAC chips of the same type, you could select one that happens to be better than the first individual you tried. They don't seem to sell a higher-spec version of an identical chip, so it's unlikely that the manufacturer pulled out the best ones to sell under a different model number or something.

Swapping in a chip with higher resolution seems like it might be do-able because Microchip does sell 10-bit and 12-bit versions with the same pin-out. It would require a firmware change. The point isn't really to get more bits because you only actually *need* seven bits to cover the 120 notes in ten octaves... but since the linearity ("tracking") is related to the bits, the more-bit chips will also have better linearity.

I'm not convinced that you can really keep the other parts of an analog synthesizer accurate enough for this to be the limiting factor on tuning accuracy, though. And as long as you're using 12-tone equal temperament, you're in some kind of a state of sin, with all your major and minor thirds off by about 15 cents as a basic feature of the tuning system. If you want really really accurate tuning, you should go digital and microtonal.
flts
mskala wrote:
I'm not convinced that you can really keep the other parts of an analog synthesizer accurate enough for this to be the limiting factor on tuning accuracy, though. And as long as you're using 12-tone equal temperament, you're in some kind of a state of sin, with all your major and minor thirds off by about 15 cents as a basic feature of the tuning system. If you want really really accurate tuning, you should go digital and microtonal.


The thing is though, that how much the tuning will be "off" in "perfect" equal temperament will still be according to design of the tuning system. So the error is one that is expected and one that most peoples' ears are used to. And, most importantly, one that should be consistent from one instrument from another, so that you may expect two instruments playing simultaneously to be in roughly in tune with each other on each note.

A (consistent) 20 cent deviation from expected tuning on one or more notes inside an octave is definitely a lot bigger than what I expect from a properly calibrated analog oscillator driven by a reasonably accurate CV source. And I can't say I'd be a "golden eared" person or one that would complain if something is just a bit off here and there.
gbiz
I'd agree with getting another DAC & trying that. The things are cheap enough it's probably worth getting a few & picking the one that gives you best linearity across the range of output voltages you intend using the quantiser for.


I've seen similar behaviour with Microchip's 4922 in a dual channel quantiser i've built. I use lookup tables for the octaves & quarter notes. I have a calibration routine that provides the ability to tune the ten LUT settings for the ADC input & DAC output octave voltages. What i've found is theres a lot of linearity variance not just between chips but also channels in an individual chip. Some were shockingly bad. And the non-linearity wasn't just at the ends of the chosen DAC output range, sometimes there'd be noticable bumps midway through.

I didn't both with a calibration routine for the quarter note LUTs, partly due to the lack of resolution with the 12-bit DAC, but mostly after a couple of days of repeatedly calibrating 2 x 2 x 10 settings for the octaves on the bench, i lose the will to live. hihi
clusterchord
flts wrote:
The thing is though, that how much the tuning will be "off" in "perfect" equal temperament will still be according to design of the tuning system. So the error is one that is expected and one that most peoples' ears are used to. And, most importantly, one that should be consistent from one instrument from another, so that you may expect two instruments playing simultaneously to be in roughly in tune with each other on each note.

A (consistent) 20 cent deviation from expected tuning on one or more notes inside an octave is definitely a lot bigger than what I expect from a properly calibrated analog oscillator driven by a reasonably accurate CV source. And I can't say I'd be a "golden eared" person or one that would complain if something is just a bit off here and there.


exactly. i just need Penrose accurate in equal temperament world. for example, my old SEMs stray only 1 cent at 4 octaves. this allows me to play them along other instruments. something like 258J probably less. i can deal with these deviations more easily if i know the signal coming from the quantizer is accurate. it reduces the number of variables.



on a related note, microtonality always interested me, but is a whole different kettle of fish - i would love an accurate microtonal quantizer, with scala file support and user editable tables. another thing that is a total game changer is feedback capability to do auto calibration, like expert sleepers does. it plays-then-listens to your oscillator and adjusts the v/oct curve on several points to compensate for any deviation. alas, things like that are probably only realistic in software not euro.
flts
clusterchord wrote:
another thing that is a total game changer is feedback capability to do auto calibration, like expert sleepers does. it plays-then-listens to your oscillator and adjusts the v/oct curve on several points to compensate for any deviation. alas, things like that are probably only realistic in software not euro.


fwiw out of commercial offerings beside expert sleepers, http://analoguesolutions.com/clarke/ the asol/clarke midi interface does this, so did the (long ago discontinued?) metasonix midi-cv i think. only the es one relies on being hooked up to a computer.

of course there's extra complexity involved if you apply that idea to a quantizer where "ideal" v/oct input should produce a quantized cv output that's compensated with a curve or lookup table based on oscillator frequency detection using a set of automatically fed output voltages. compared to a midi/cv interface where the source control data is digital, you'd need an accurate analog-to-digital conversion step for cv in as well, otherwise you can't really trust that the relationship between input and output is the correct one i guess.

however, i don't see why it wouldn't be possible in euro as well - we already have a large bunch of pretty elaborate digital modules out there with high quality ad/da and reasonably powerful mcus like stm32f4. the result would in essence be a quantizer with extra input for creating the quantization table automatically based on oscillator base frequency analysis and with simple waveforms, base frequency analysis isn't terribly elaborate or cpu intensive.
fuzzbass
atte wrote:
I'm pretty sensitive to out of tune errors, and haven't found anything wrong with my Penrose. I'm planing on getting another...


I'm just tone deaf enough for it to work for me! I'm planning on getting a second one too. Being in correct pitch is highly overrated anyway, strictly for people auditioning for "The Voice".
batchas
Comboy wrote:
Here is a picture showing the signals on the PCB.
Please note that the left and right jacks have a different orientation.


On was a bit too fast on this project and made realy mistakes (banana version. Did not read this thread before).

Could you please tell me where the TRIG IN signal is going to (J4 trace number 3 in your pict)?
Is it going to JP1 pin?
BugBrand
If I remember right - trig in goes direct in to the tip connection, but there is normalisation for the ring connector - when a mono plug is inserted, it connects to ground. I think I mentioned that in my banana bits a while back, no?

So - to clarify (just got your PM!) - tip goes to pin3 of J4, then you have a switch going from pin2 (ring) to pin5 (gnd)
batchas
BugBrand wrote:
If I remember right - trig in goes direct in to the tip connection, but there is normalisation for the ring connector - when a mono plug is inserted, it connects to ground. I think I mentioned that in my banana bits a while back, no?

I cut the traces on the IN pad, so I don't see where the tip is going. This is my problem, so I don't know where to connect the switch directly to.
batchas
BugBrand wrote:
And whacked on 7812/7912 for regulation down to +/-12V [funny, 'cos I looked over the schems and thought it may work fine direct from +/-15V but something was acting weird, so...]

I don't understand this part if we want to use the Penrose with +/-15v.
Is the 78L05 not meant to take the 12v and lower them to 5v?
Aren't we producing 12v when we take a 7812 or 7912?
Should we not use a regulator which takes the 15v at the input and lower them to 5v instead?
Confused noob question smile
batchas
Also found out a bit too late that for the banana version, I'm gonna need a switch in place of normalization for the TRIG IN. And that I should not have soldered a socket, cause I have to solder the TL072 backwards, on the other side of the board d'oh!

À propos being too fast and not taking really care of ever details BEFORE populating.
batchas
batchas wrote:
I have to solder the TL072 backwards, on the other side of the board d'oh!

Ok. Done. Only took a few secs.
Not so dramatic!
ArguZ
Hi guys ,

i just wanted to chime in that i am having the same input scaling issues.
Someone mentioned it would be best to remove the 49k9 and replace it with a 48k and a proper 2K trimmer.
I am also using the BeatStepPro and it bugs me that the digital precision of it does not ripple down the line.
Of course, feeding the Penrose with analog sources requires a lot more wiggling.
I am using an Ryo Attenuator to limit the voltage to 99,5% which takes care of the scaling...
One guy in the Penrose forum suggested changing the firmware accordingly, so adding a scaler per software.
Personally i favor the input calibration solution with a trimmer.

Oh, hey atte, i am in CPH too, maybe ot scaling issue is a geographical one :-D
atte
Yeah, there's something rotten in the state of Denmark!

Not sure why why you would prefer hardware over software fix. It's simply one line of code, and it Just Works.
batchas
batchas wrote:
I cut the traces on the IN pad, so I don't see where the tip is going. This is my problem.

I guess this is not clear because of my english: what I mean is, I don't see where it is coming from.

I did cut the trace on the IN pad, so I don't see where the TRIG OUT goes on the board (the source of the signal).

If it was an OUT I could check all points with a scope, but it's a IN and I have no schematics.

Any help with that very appreciated.
BugBrand
You can see the traces on the image..



Tip is pin 3 of each jack.
0V is Pin5 , ring is pin 2 (4 is probably tip switch?)

If, for example, you managed to cut the INPUT trace which passes under J4, then you can see that it has vias up at the top/right of J4 - just take the signal to there. Think there are easily available jumpers for each point.

Guessing that J4 pin2 (ring) has a pull up resistor to +5V - this is pulled to ground when a plug is inserted. (or when you use a switch).

I'm sure schematics & board files are available somewhere (github) - view in eagle.
batchas
Thank you Tom! I appreciate you take time here, though I acted stupidly on this project. Fast, without light and not even checking before cutting in the board. Plain stupid.

I found the drum project from Sonic Potions on github, but not the Penrose schems.

EDIT:
all is OK now like I mention in a later post.
batchas
batchas wrote:
I found the drum project from Sonic Potions on github, but not the Penrose schems.

Oh zombie

I found while searching "penrose quantizer" instead of "Penrose" or "Sonic Potions":
https://github.com/SonicPotions/Penrose

Let's see if there are schematics there...


EDIT: Nope. No schematics there.
pld
The schematics weren't in github last I checked, but they are linked from the assembly guide: here
batchas
Thanx pld!!!

I read once more my questions and looked again at the pcbs. Mostly cheked the photo I posted again too. I think it's obvious that the TRIG IN can only go to JP1! Sometimes I just worry too much seriously, i just don't get it

I'll verify via schematics, but I also realize that I could also have simply tried to send a TRIG there. The risk to harm anything being really low anyway.
Mea culpa.
batchas
So. I check the schematics. ALL OK now. TRIG IN goes to JP1. I verified.

Sorry for bothering with all my posts for something I could have checked more carefuly without need to ask.

@Tom: also please accept my apologies.
BugBrand
Really?!
Oh, I see what you mean - was getting confused between J1 (CV In) and JP1 (inter-board connector).
Yes, all top board traces go back to JP1 - either direct (or via passives) or to opamp stages before JP1.
Zymos
sonicwarrior wrote:
atte wrote:
... Except it should be possible to turn buttons off...

It is possible, just not with the currently played note button. Just tested it with an offset voltage and the red LED is moving around and the button can be turned off after it's green again.
I find this behavior a bit strange but I guess it's normal?


So is it normal?
Just finished my build, and mine does that too.
Got it calibrated and gave it a quick test, everything seems OK.

Was a bit bummed I'd be in for a bunch of troubleshooting when I plugged it in and saw that one red light that I couldn't turn off....
schwittersplayspop
nebula 80 wrote:
Just finished my Penrose build. Everything seems to work.
Except 4 buttons don't light up.

I resoldered already the buttons. Nothing has changed.

Any ideas on what and how to fix this issue?

Daniel


I have a similar issue -- three buttons, top 2 on the left and top 1 on the right -- don't light. Have resoldered the buttons, and nearby resistors, and all looks OK on the board. Does anyone know if those three buttons are dependent on a particular component? Thanks!
atte
mskala wrote:
Swapping in a chip with higher resolution seems like it might be do-able because Microchip does sell 10-bit and 12-bit versions with the same pin-out. It would require a firmware change.


The tuning errors are starting to get on my nerves as well.

Could you point me to a 12 bit replacement chip, maybe on mouser? The firmware I can handle I think...
mskala
atte wrote:
The tuning errors are starting to get on my nerves as well.

Could you point me to a 12 bit replacement chip, maybe on mouser? The firmware I can handle I think...


Here it is: http://www.mouser.dk/ProductDetail/Microchip-Technology/MCP4821-E-P/?q s=sGAEpiMZZMswix2y39yldQRiesmyAwEfqZLAbaleMWU%3d

But the inherent nonlinearity of that chip is only rated to be +-12 LSB worst case, which is not meaningfully better than the original chip when you figure that one LSB count at 8 bits is equal to 16 counts at 12 bits. To guarantee better output accuracy than with the 8-bit chip, you're either going to have to select chips (in which case you'd be better off with the 8-bit chip: cheaper, and so you can afford to buy more of them to test) or else do per-step calibration, which might require more significant work on the software side and maybe a different microcontroller with more nonvolatile storage.
atte
Thanks mskala! So what you're saying, is I actually need a link to a the original 8-bit DAC, so I can buy a bunch and test my luck. Anyone could share a link to mouser?
mskala
Well, I don't know the specs of the microcontroller. If it has enough spare space for program and nonvolatile memory, doing per-step calibration might be a real possibility. Or something in between, like what a Mutable CVpal does - several points and linear interpolation between them. You said you were willing to hack the firmware, so you probably have some idea of what its capabilities actually are. And that 12-bit DAC *will* do what you want, with no other hardware changes, if you feed it the right numbers; it's just that those numbers will have to be calibrated for the individual DAC chip.

The 8-bit DAC is http://www.mouser.dk/ProductDetail/Microchip/MCP4801-E-P/?qs=%2fha2pyF aduh9QjXTGCkBssTPd7IhLfUjIrjzakjlt50%3d.
Suppish Mode
Arrived today, it's my first DIY kit! w00t
Not a complete n00b in soldering, but I'm still pretty nervous. Hope that little potion bottle that arrived with parts will bring me luck)
And thanks for Camel Balls! SlayerBadger!
atte
Ok, my 3 8-bit DACs have arrived, hope to pop them in tomorrow.

Meanwhile another solution came to mind: If I could scale the output to 0-5V (accompanied by a change to the fw) the errors would be cut in half. However the trimmer wont let me go this low, what hardware hack should I apply to achieve this?
atte
Ok, here are the results of my highly unscientific tests:

All three DACs fared better than the one that came with the kit. One slightly better, one "above average" and one quite good. The two best ones are acceptable, the best is a keeper. I graded them (0-10): 2, 4, 6, 8.

With the original one most notes would be sharp or flat, about 10 notes as much as 30 cents. The best one has 95% of the notes below 5 cents, with a couple of by 10 cents.

For the test I used a BeatStep Pro, an orgone accumulator (but also A-110 and Z3000), a CED tuner and my computer based tuner.

For me this boils down this:

1) I'm now perfectly happy with my penrose, and will get a second one soon.

2) It pays off to buy additional DACs and select the best one, esp since they're only about a euro each.
matcsat
Hi !

Today i tryed to build a penrose, and everithing went fine: all buttons lighting up correctly, CV input work fine (5V engage 5 time the octave range), trigger in and gate out work correctly.
The big problem is on CV out: the range of 1 octave is too much short, like it is scaled down,"shortened" if its better understandable.

So i think the problem is in the CV output path, sadly i don't have real EE skills: probably i was lucky when i build the radio music module and everything worked fine.

The soldier job isn't horrible or excellent, just fine.

Any suggestions ? Need more info about my situation ? Image or anything else ?

Thanks in advance for any help.

Marco.
atte
Have you calibrated using the trimpot?
matcsat
Hi.

Actually the trimpot is another problem, it doesn't do nothing.
Sorry i forgot it.

I read somewhere that the trimpot act in very minimal range, so my problem seem too big for it.

The octave jump on CV out became a 1/3 of normal value.

Normal behaviour: 1000 Hz / 2000 Hz / 3000 Hz / etc.

My situation: 1000 Hz / 1340 Hz / 1680 Hz / etc.

There consistency in that behaviour, good for microtuning maybe ?! waah

Marco.
Altitude909
how are you testing? With only one button lit, what is the voltage difference on the output when it jumps when you increase the voltage on the input? It should be 1V
Useful Noise
A very easy build, actually a lot easier than I anticipated. Might have to get a couple more. Don't think I can go back to using knobby quantizers now! razz
matcsat
Altitude909 wrote:
how are you testing? With only one button lit, what is the voltage difference on the output when it jumps when you increase the voltage on the input? It should be 1V


Using frequency counter on windows (soundcard scope) and vst C_Tuner.
Triatt DC constant voltage out - penrose CV in
only 1st button on top activate
Penrose CV out - dixieII 1v/oct in
dixieII tuned at 1000 Hz
dixieII suqare out - pitt in/out in
pitt in/out out - soundcard

With triatt i putt constant voltage into penrose, over the entire range of triatt pot i see 5 time penrose engaged from volt to volt, so the cv input behave good.
At the output of penrose the voltage seems downscaled.
Instead of increment of 1000 Hz (1000/2000/3000/etc) i have 1000/1340/1680/etc.

I had search in this forum and in official one of penrose, but nobody seems encounter such problem, unlist not exatly the same: one guy had problem with trimpot doesnt work, same as my trimpot, but nobody respond to him.
Thats the cloosest one.

In the meantime i do another check of soldier and components.

Marco.
batchas
I had a trimpot issue, but only because I cut many traces whie drilling holes for bananas.
If someone without modular reads this, he will think "why drill holes to grow bananas???"
atte
matcsat wrote:

Actually the trimpot is another problem, it doesn't do nothing.
Sorry i forgot it.


I'd say the trimpot is at the heart of your problem, there should be alot of audible change when adjusting it. Can you check for continuity (there shouldn't be any) between outer solder joints of trimpot.

Could you post a few close ups of top/bottom of each PCB?
matcsat
Hi

I was read that the trimpot act in a small range, so i assumed that isn't correlate to the big downscale of CV out, my mistake.
Anyway.

This is my two board finisced:





How i test continuity of trimmer ? Technically !

Thanks for reply and suggestion.

Marco.

P.s.

I hope the images aren't too big.
atte
Continuity can be checked with a multi meter. A few joints look like they could need some touch up, some look so close to the next on, you wanna make sure they're not touching.

Did you try posting on the Penrose forum?

Besides that I unfortunately can't help at this point, Christmas holiday in minutes w00t
matcsat
Hi

I actually registered into penrose forum but it seems impossible to reply to any post (Commenting not allowed) or made new one (i didn't see any button "new topic" or similar), all funtions are disabled, i don't know !

I checked the soldier points and they didn't touch each other.
For the bad joints i'll do some resoldering and will see if something happen.

Thanks again.

Marco.
CeeJay
50% of your solder joints look like they have no good connection. Too less solder on most of them. I think resoldering with additional solder will solve your problem.
matcsat
hi

I just reesolder many joints, but nothing changed.

The trimpot do not work at all, i did a continuity test on it and i had some multimeter reading on all 3 soldier points.

What that's mean ? Must be replace it ?

Marco.
atte
No continuity is good! How about checking values of all resistors, looking at color codes?
matcsat
hi

Maybe i found the problem:

I swapped three resistors.

I have:

R24 at 10K instead 221 ohm.
R5 at 221 ohm instead 1k.
R17 at 1k instead 10k.

I need to purchase new ones because the legs are too short after soldered them.

I'll let you know how it ends ?

Thanks for the help.

Marco.

P.s.

I am colorblind so i asked help to my brother ... i think he need optical visit.
atte
I glad to hear you made Som progress. I'm not a DIY wizard by any means, but I suggest you get a multi meter if you are planning on building more stuff, esp since you're color blind. I measure all resistors before soldering, a bit OCD, I know, but better safe...
matcsat
Hi

I have a multimeter, i dont know why i ask help for color code instead to check resistor value myself.
Im not a DIY guy, the obvious think seems to slips out of my mind.

But im happy for did not gave up.
Now crossfinger for happyend.

Marco.
atte
Ok great. Remember that you cannot measure resistors that are soldered to the PCB
matcsat
Hi

I managed to desolder the three wrong resistor and put them into they're right place.

But nothing happened, i have exactly the same behaviour.

One thing: i check resistors value with the multimeter; the resistors was still soldered on board and i read a value, then i desoldered them and check again and the value was the same.
For example the 10k resistor show his value exactly the same when on board and when out of the board.

Still the trimmer is dead.

I think i cannot manage this project at this point.

I take breath and will decide.

Marco.
atte
If possible, desolder the trim and measure it with your meter.
matcsat
Hi

I'll try.

In the meantime: how you explain the multimeter work fine if the resistor is on board and the same if it not ?

Marco.
atte
Its possible to get correct measurements with resistors om PCB, you just vant rely om it. Depends on PCB layout...
matcsat
Thanks !

Didn't know !

Marco.
matcsat
Hi

It work !

Remove and put back the trimmer solve the problem !
Calibrated perfectly.

One last thing, even if it doesn't bother me too much: when i connect penrose CV out to V/Oct in of my two oscillators (DixieII and Doepfer 110-4) i hear some distortion on waveform, not loud but i definitely heard it. More in DixeII than 110-4.
No one else ?

Thanks for the help.

Marco.
atte
Great to hear w00t

The only thing i can think of is Penrose not beimg able to decide which note to choose. Does it disappear or change with different selection of notes on the Penrose. I think there's a firmware fix for this...
matcsat
Hi.

It was false allarm: bad cable.

After 24h it's all fine: no heat, no smoke, i think i can relax now !

Really fun module BTW.

Bye

Marco.
atte
w00t
sonicwarrior
Anyone care to share their calibration measurements?

I finally calibrated my Penrose and here are my measured values:

Input voltage source: Doepfer A-185-2

Direct output: 0,001 V
Penrose output: 0,004 V
+1: 1,006 V
+2: 2,002 V
+3: 3,003 V
+4: 4,000 V

I could have the +1 octave at better values at cost of less accurance on the higher octaves so this seemed to be the best compromise.

Measured with a Fluke 179 which should be pretty accurate.
Maxx mayhem
I built one the other night, and was quit impressed with the kit. It lights up, waiting for my PSU module back to really try it out. The panel is excellent, only suggestion, I waited to solder the switches until I had all the front panel components in place and the jack nuts down. The instructions said to solder the switches first, though that could result in alignment issues. As it was, all went together perfectly the way I did it.
Zymos
On mine, the threaded post welded to the back panel was slightly off. There was no way everything could line up correctly, the buttons were all tweaked at an angle and wouldn't operate smoothly.

Luckily I came up with a solution- reamed out the hole on the circuit board that the screw passes through, and then could put it all together perfectly square.
adnauseam
I've had a penrose for a while and while I was initially happy with it I've found it's not really all that accurate, especially when paired with another quantizer. They don't change notes together accurately when the same input voltage is sent to both via a buffered mult. My other quantizer is a uScale II.

Kind of frustrating. I've found I need to amplify the same voltage for it to track accurately with the uScale II. And so my search for input scaling via software begins!

I've just now replaced r21 with a 10 ohm resistor so my gate output voltage is good now.



Interesting to hear that atte has had good results by changing DAC chips. This affects the output scaling but not the input scaling.


Comboy: it would have been nice to have the resistor change documented somewhere more official. I had to look through your forums for the answer when you could have it on the penrose page itself. Perhaps you need a change log directly on the page.

Cheers
sonicwarrior
adnauseam wrote:
Comboy: it would have been nice to have the resistor change documented somewhere more official. I had to look through your forums for the answer when you could have it on the penrose page itself. Perhaps you need a change log directly on the page.

What exactly does replacing R21 with 10 Ohm resistor change (original value: 1k)? hmmm.....
adnauseam
sonicwarrior wrote:
adnauseam wrote:
Comboy: it would have been nice to have the resistor change documented somewhere more official. I had to look through your forums for the answer when you could have it on the penrose page itself. Perhaps you need a change log directly on the page.

What exactly does replacing R21 with 10 Ohm resistor change (original value: 1k)? hmmm.....


If you have version 0.3 or earlier (which I do) the gate is something like 2 V instead of close to 5V. Changing the resistor to 10R fixes the gate to output a normal voltage.

That is all!
sonicwarrior
Thanks, I have version 0.4 boards so it seems I'm good.
Suppish Mode
Quote:
adnauseam wrote:
Comboy: it would have been nice to have the resistor change documented somewhere more official. I had to look through your forums for the answer when you could have it on the penrose page itself. Perhaps you need a change log directly on the page.

What exactly does replacing R21 with 10 Ohm resistor change (original value: 1k)? hmmm.....


If you have version 0.3 or earlier (which I do) the gate is something like 2 V instead of close to 5V. Changing the resistor to 10R fixes the gate to output a normal voltage.

That is all!


Mine works fine except gate out. When turning on it works, but in a minute or so LED light fades out completely and voltage falls. Maybe problem in mentioned R21, but I have version 0.4, so it seems unlikely.
Any suggestions? help
drsm79
Hi,
I built one of these at the weekend. The "keyboard"" lights up when I press buttons but I can't get it to change notes via a signal to the IN (it does change the OUT voltage if I turn notes on and off). Any suggestions on how to debug? I can't see any dry joints, and the fact that things are lighting up and pitch is changing make me think things aren't far off working...
atte
drsm79 wrote:
Hi,
I built one of these at the weekend. The "keyboard"" lights up when I press buttons but I can't get it to change notes via a signal to the IN (it does change the OUT voltage if I turn notes on and off). Any suggestions on how to debug? I can't see any dry joints, and the fact that things are lighting up and pitch is changing make me think things aren't far off working...


Check esp jack in and orientation of all ICs. Maybe post pictures of both sides of both PCBs??
cupwise
could someone point the way to a cheap programmer for the atmega chip? i've never programmed a chip so i have no idea what i'm looking for and getting a bit confused by the various things i'm seeing when i search.
atte
If you mean for the Penrose no programmer is needed, just playback the firmware through the trigger in...
cupwise
hmm, ok. i asked because someone on page 4 asked if the pcb included the chip and comboy replied:
Comboy wrote:
you mean the atmega? No, but the .hex file to flash it yourself is available on github: https://github.com/SonicPotions/Penrose/raw/master/bin/FirmwareAndBoot loader.hex

I could add a chip, but in general flashing them is very easy and a good avr programmer is only about 5€.


whats that mean?
CeeJay
If you sourced the ATmega chip yourself, then you need a programmer. Just search for AVR ISP (MKII) or compatible. Make shure it has a 6 pin connector.
If you bought a kit, then the chip is already flashed with the firmware.
Firmware programming via the trigger in is only possible for further updates.
cupwise
atte, did you ever think any more about the idea of halving the voltage range to improve the accuracy? any idea what would be needed? just a different value trimpot maybe?
atte
cupwise wrote:
atte, did you ever think any more about the idea of halving the voltage range to improve the accuracy? any idea what would be needed? just a different value trimpot maybe?


Not really. The pot wouldn't let me scale output as much as needed. And since I was really happy with the replacement DACs, I didn't investigate further. Just finished my second penrose this weekend, and the DAC in that one is ok. I'm gonna build a few more soon, and plan on getting additional DACs to select the best ones from.
charonme
turns out the output trigger pulse from the penrose is often too short to trigger the grayscale algorhythm which needs at least 10ms. I hope lenghtening the pulse should be as simple as changing one constant in the source code...

Also, is there a way of uploading new firmware using the standard serial or SPI on the atmega while still connected in the module (instead of the audio transfer)? I have both FTDI and SPI arduino programmers.

BTW I noticed for some CV input voltages the quantizer can't decide what to do with them so it outputs a stream of triggers and two adjacent buttons light up. Possibly there is a tiny fluctuation in the input CV, but I would expect a quantizer to not change the note when the difference is just a few cents
pld
charonme wrote:
turns out the output trigger pulse from the penrose is often too short to trigger the grayscale algorhythm which needs at least 10ms. I hope lenghtening the pulse should be as simple as changing one constant in the source code...

IIRC the gate output is wired to the update pin on the DAC, so there might be some tradeoff there. But algorhythm needing a 10ms pulse is good to know, that explains some things smile

Quote:
Also, is there a way of uploading new firmware using the standard serial or SPI on the atmega while still connected in the module (instead of the audio transfer)? I have both FTDI and SPI arduino programmers.

There's the ISP header?

Quote:
BTW I noticed for some CV input voltages the quantizer can't decide what to do with them so it outputs a stream of triggers and two adjacent buttons light up. Possibly there is a tiny fluctuation in the input CV, but I would expect a quantizer to not change the note when the difference is just a few cents

There is some hysteresis built-in, and there has been some discussion about the behaviour here already. I made a quick attempt to tame it a while back, but that thread has at least one other variant. The ADC in the AVR is more the culprit that the input voltage.
drsm79
atte wrote:
drsm79 wrote:
Hi,
I built one of these at the weekend. The "keyboard"" lights up when I press buttons but I can't get it to change notes via a signal to the IN (it does change the OUT voltage if I turn notes on and off). Any suggestions on how to debug? I can't see any dry joints, and the fact that things are lighting up and pitch is changing make me think things aren't far off working...


Check esp jack in and orientation of all ICs. Maybe post pictures of both sides of both PCBs??


Sorry for the slow reply - returning to work has taken time away frmo soldering wink




When I built the kit I mistakenly put the power connector on the wrong side of the board (tired), I've since removed that and put it on the correct side. Things light up etc. but I wonder if in doing that I've fried something.
charonme
is it normal that some button combinations don't work properly or is my build flawed?
If it's normal, is this a SW bug or a HW issue?
Hjorten
Slowing putting this thing together; in the assembly guide it says that the 10 uF tantal capacitor (C14) should have one leg longer than the other, and mine doesn't. It does, however, sort of have a blob directed toward one leg, is that the positive leg?



*edit: added photo.
sonicwarrior
There is a small + on the plus side. Above the 16.
darylc
some possibly stupid questions!

For the quartz isolator disc can i use any bit of plastic to separate it from the board ?

Also for the quartz, i have some that are 18pf and some that are 18-22pf, can i assume the 18-22pf can take any cap in that range or is there some set of measurements i need to take ?
purple_elk
Hi,
I've just built my penrose and the only thing which seems to be working is the gate. If I send a gate signal to gate, it lights up and if I have nothing connected then it is constantly on.
None of the LED buttons light up and nothing is coming out of the 'out' jack no matter what I put in.
All polarised components are orientated correctly.
Any help / suggestions greatly appreciated.





[/img]
purple_elk
By the way, before I attached the two boards measured continuity
between -ve and ground
+ve and ground
and -ve and +ve

and there was continuity between all three! This does not seem right, right?
medbot
purple_elk wrote:
By the way, before I attached the two boards measured continuity
between -ve and ground
+ve and ground
and -ve and +ve

and there was continuity between all three! This does not seem right, right?


You should definitely not have continuity between your power rails. Check for component legs touching or solder bridges and give your board a cleaning to make sure it's not some flux somewhere causing the problem.
antf4rm
I find that cleaning up the board with a dull dental pick and a brush provides a great opportunity to spot suspect joints and potential bridges.
purple_elk
Is it possible to delete one's messages on this forum?
purple_elk
I accidentally made a couple of posts I want rid of, it will let me edit it but I can't see a way to delete
purple_elk
purple_elk wrote:
medbot wrote:
purple_elk wrote:
By the way, before I attached the two boards measured continuity
between -ve and ground
+ve and ground
and -ve and +ve

and there was continuity between all three! This does not seem right, right?


You should definitely not have continuity between your power rails. Check for component legs touching or solder bridges and give your board a cleaning to make sure it's not some flux somewhere causing the problem.


What is it about flux that could cause problems?
UniversalSolder
Hi !
Oups, I did shit with R14, the pads are destroyed. Is there a way to connect it somewhere else with some thin cable ?

If yes where ? Or is there a way the get the schematics of the PCB ?

thanks
bovaflux
Just built a couple of these and also noticed that I'm having some issues with dodgy tuning. It seems good for 3 or maybe octaves, but beyond that it'll start selecting notes a little off from what I'm expecting, or even failing to settle on one particular note at all... confused If I use it with a plain sequencer then it's not too noticable, but if I try playing it with my microbrute then it shows up the problems very quickly (c-0, c-1, c-2 are ok, c-3 quntizes to c#3). I don't think this is a callibration issue, as I've gone through that multiple times and it seems to be pretty spot on now..

Wondering whether to also try getting a few additional DACs to try out and see if it improves things?
fhars
It's a problem with the "calibration" of the CV input stage, which is done by relying on resistors with 1% tolerance and assuming that the voltage regulator produces exactly 5V. So the input stage can be off by a semitone every few octaves. You can compensate the error with a correction factor in the firmware, there is some discussion on the penrose forum: http://forum.sonic-potions.com/discussion/761/penrose-build-problems/p 1

(Since all seem to be in the same direction, it is probably something systematic with the reference voltage and not random resistor values.)
bovaflux
The problem described in that thread is exactly what I've been seeing, and the hacked firmware works perfectly. Thanks for that link, and thanks to the guy that made that tweaked firmware available! It's peanut butter jelly time!
bovaflux
Urgh, so it looks like I spoke too soon! That hacked firmware (which scales the input by 98%) worked perfectly on one of my quantizers, but for my other penrose it's over compensating. I think I probably just need it scaled by 99% for that one. Very frustrating. I'll have a go at doing my own firmware hack, although I've not done this kind of thing before so if I do manage to get a development environment set up (tips anyone?) hopefully I won't corrupt the module's firmware or anything! :(

Would be much easier to have a trimmer on the board to scale the input instead!
bovaflux
UniversalSolder wrote:
Hi !
Or is there a way the get the schematics of the PCB ?
thanks


http://www.sonic-potions.com/public/PenroseQuantizerSchematic.pdf
Altitude909
wouldn't be easier to just add a pot to trim the +5 or add a better reference?
fhars
Altitude909 wrote:
wouldn't be easier to just add a pot to trim the +5 or add a better reference?


Changing firmware (especially an open firmware like the penrose's) is almost always easier than adding a trimmer or a precision voltage source to someone else's PCB. And I think the firmware should have a calibration mode where you play some Cs in different octaves from a known good CV source and it calculates the input calibration constant on its own.
bovaflux
Well I'm a bit of a noob with hardware, but have a lot of experience with code, so I'm leaning towards that solution currently (especially as one version of the hacked firmware sorted out one of my Penroses). Plus I don't have any suitable spare parts (or much of a clue how I'd hook that into the existing module).

I've got as far as generating an updated .hex file, but can't seem to get the makefile to correctly build the tool for converting that to a wav. It gives me the unhelpful error message "make (e=2): The system cannot find the file specified", without saying which file that is.. confused So close!
UniversalSolder
bovaflux wrote:
UniversalSolder wrote:
Hi !
Or is there a way the get the schematics of the PCB ?
thanks


http://www.sonic-potions.com/public/PenroseQuantizerSchematic.pdf


Thank you so much !!

Unfortunately, I can't find the R14 on this schematic ...

Any help would be appreciated !
sonicwarrior
UniversalSolder wrote:
Unfortunately, I can't find the R14 on this schematic ...

Page 2, the 100K in the feedback of U2B.
sromanel
Hi everyone, I'm about to buy one, is there any known issue I should be aware of? I've read there's this "undecided-ness" problem, does it occur on everyone's module or did it only happen to some of you? In case it constantly happens, how should it be fixed?
UniversalSolder
sonicwarrior wrote:
UniversalSolder wrote:
Unfortunately, I can't find the R14 on this schematic ...

Page 2, the 100K in the feedback of U2B.


Hum, sorry, did not see the page 2 ! d'oh!

Thanks !
fhars
It should be fixed by adding a calibration mode to the firmware, but can be fixed by checking how far off the quantisation is for higher notes and then recompiling the firmware with the correct calibration factor. (Note that this is only a problem if you quantise alredy pitch correct voltages, if you just quantise some random voltages it doesn't matter at all.)

And there is a possible problem with the ADC. According to the datasheet, it has a typical maximal error over the whole range corresponding to about six cent. Unfortunately, the manufacturers only guarantee a worst case maximal error corresponding to six semitones. So if the output is a off, you may have to change the ADC.
adnauseam
sromanel wrote:
Hi everyone, I'm about to buy one, is there any known issue I should be aware of? I've read there's this "undecided-ness" problem, does it occur on everyone's module or did it only happen to some of you? In case it constantly happens, how should it be fixed?


Honestly, I haven't heard about a specific problem with Penrose. This "undecidedness" problem occurs with all quantizers. Scale the input a tiny bit, and maybe a tiny bit of offset will fix this 99% of the time.

My uScale occasionally fluctuates rapidly between notes, and so did my doepfer a-156 at times. Scale, offset, fixed.
mskala
It seems like the fluctuation could be fixed by adding a little bit of hysteresis to the conversion. When the signal goes above a boundary, move that boundary down a little so that the signal has to really change direction in order to cross again, and vice versa. That should be possible with smarter firmware.

If the input-to-output scaling is correct (which is the other issue people were talking about just now) you could create such hysteresis without changing the quantizer by creating a feedback loop: mix the signal to be quantized with a small amount of the quantizer output and use the result as the quantizer input. That way it'll tend to be attracted more to its current note and less likely to fluctuate.
bennelong.bicyclist
mskala wrote:
It seems like the fluctuation could be fixed by adding a little bit of hysteresis to the conversion. When the signal goes above a boundary, move that boundary down a little so that the signal has to really change direction in order to cross again, and vice versa. That should be possible with smarter firmware.


That's exactly what the quantiser in the Mutable Instruments Braids module does - see https://github.com/pichenettes/eurorack/blob/master/braids/quantizer.c c#L98

- and it works very nicely. Braids also provides a settable delay, measured in microseconds, between a new-note gate/trigger being received and the quantiser sampling the pitch voltage - the allowing pitch CV sources to settle a bit before sampling it for quantisation. Implementing both of those measures is best practice.
sromanel
Thanks everyone for the replies, it doesn't seem to be a dealbreaker
bovaflux
No, don't let these issues put you off, it's still a great little module. smile
charonme
sromanel wrote:
is there any known issue I should be aware of?
one of the things I noticed is that pressing multiple buttons don't work as expected
sromanel
charonme wrote:
sromanel wrote:
is there any known issue I should be aware of?
one of the things I noticed is that pressing multiple buttons don't work as expected


Care to explain a little further?
fhars
sromanel wrote:
charonme wrote:
sromanel wrote:
is there any known issue I should be aware of?
one of the things I noticed is that pressing multiple buttons don't work as expected


Care to explain a little further?


It is implemented as a typical scanning keyboard matrix with firmware designed to recognise the press of one button at a time (gamers would call it 1-key rollover), so you would expect a two key press to be recognised as one or the other or a third button entirely depending on which two buttons you press. It is just undefined behaviour.
sromanel
fhars wrote:
sromanel wrote:
charonme wrote:
sromanel wrote:
is there any known issue I should be aware of?
one of the things I noticed is that pressing multiple buttons don't work as expected


Care to explain a little further?


It is implemented as a typical scanning keyboard matrix with firmware designed to recognise the press of one button at a time (gamers would call it 1-key rollover), so you would expect a two key press to be recognised as one or the other or a third button entirely depending on which two buttons you press. It is just undefined behaviour.


So, if I got this right, we're talking about doing something it's not meant to recognize, right?
fhars
sromanel wrote:
So, if I got this right, we're talking about doing something it's not meant to recognize, right?


Right.
sromanel
fhars wrote:
sromanel wrote:
So, if I got this right, we're talking about doing something it's not meant to recognize, right?


Right.


No problem then Mr. Green If I'll have to quickly change scale, I'll just rapidly click the buttons instead of clicking them all at once
sromanel
By the way, does anyone know when Thonk's gonna have them in stock again?
mush
sromanel wrote:
By the way, does anyone know when Thonk's gonna have them in stock again?


Julian has Them in stock
https://www.sonic-potions.com/shop/index.php?route=product/product&pro duct_id=67
sromanel
mush wrote:
sromanel wrote:
By the way, does anyone know when Thonk's gonna have them in stock again?


Julian has Them in stock
https://www.sonic-potions.com/shop/index.php?route=product/product&pro duct_id=67


I know, but since I have to order quite a few thing from Thonk, I'd like to take advantage of that and pay just one shipment
sromanel
Double post
bleedmachine
FadingCanvas wrote:
I have been building a Penrose. I feel like a fool, but I can't get it working properly:

  • Note on/off LEDs work
  • A CV in doesn't do anything
  • The 4 highest notes change the pitch when turned on/off
  • When one of the other 8 notes is turned on, the pitch turns to the same very high tone
  • The trimmer does not seem to influence the pitch


I have got a near identical problem except for me it's the bottom end that works... The top 2/3 of the notes emit a very high tone, the bottom 4 notes are good and the lights etc are all good... Any ideas?
fuzzbass
I didn't read through all the pages here, but thought it was worth reporting...

My PQ works properly and I like it, but when using the trigger input it sometimes locks up, requiring power cycle. I have not yet figured out how
to reproduce this, but so far each instance involved a high (but below audio range) clock rate. This one was purchased soon after it appeared, so probably running the first general release version of the code.
starmandeluxe
I built mine a few months back and have been using it in almost every patch, it's very reliable. I just played a show last night using it for my main lead voice. Killer features: trig input, saves the scale into memory so it comes back even with power down. Cool look to boot. Love it! Clap
Chidori
I was scratching my head for a few days trying to figure out why mine wouldn't work. Turns out it was a faulty ribbon cable d'oh!

Also seemed to have been given a few incorrect resistor values, but I happened to have them on hand.

This thing is ace though.
TechForze
Something went wrong...
Had a functioning Penrose, but lately I noticed the normal LED will lit at 50% strength and nothing more happening.
My fault for not getting some blind panels I guess.
Checked everything by eye and I don't see any fried parts or whatsoever.
help
bonjourmyfriends
fuzzbass wrote:
My PQ works properly and I like it, but when using the trigger input it sometimes locks up, requiring power cycle.


I'm having this problem too. It happens at random using the trigger input, sometimes after short while of using triggers, sometimes after a long time.. The Penrose freezes up and stops outputting new notes/gates. I switch power off and on, and it works again.
Robscorch
Have you guys tried the latest firmware? Stopped my bricking almost altogether. Super fast/Audio rate does stick it every so often still at least for me, but after installing very few issues.

Link to Penrose GitHub
Silver
Can anyone who is fairly new at DIY tell me how this was as an early build? I'm considering it for my first DIY build. eek!

very rusty soldering skills I'm hoping to dust off.
Robscorch
Fairly easy, but the buttons can be a real pain to line up and even perfectly lined up I had to file out two of the holes a bit, but in all a fairly easy build I would say it's a 4 out of 10 difficulty.
sammy123
I agree with the above assessment.
Altitude909
Robscorch wrote:
Fairly easy, but the buttons can be a real pain to line up and even perfectly lined up I had to file out two of the holes a bit, but in all a fairly easy build I would say it's a 4 out of 10 difficulty.


use the front panel as an alignment feature before you solder in the parts
Robscorch
Even so I have built 6 of these 2 had funky panel cuts on the buttons. Mostly the middle ones. In all not to terribly difficult the worst part was getting the firmware to take that requires some audio boosting I use my Gozinta to give it that little extra go.
mskala
Robscorch wrote:
Have you guys tried the latest firmware? Stopped my bricking almost altogether. Super fast/Audio rate does stick it every so often still at least for me, but after installing very few issues.


By "bricking" do you mean locking up until power-cycled? That's not the same thing, and the difference is important: bricked means permanently unusable, not fixable by power cycle or anything else an end user can do.

Mine locks up sometimes and I was planning to try the latest firmware, but I don't want to risk it if there's a significant chance it'll end up bricked.
bonjourmyfriends
Robscorch wrote:
Have you guys tried the latest firmware?


Nope, I will give this a shot. I assumed since I ordered mine recently it would have the newest firmware, but that's not always the case. Thanks.


Silver wrote:
Can anyone who is fairly new at DIY tell me how this was as an early build?


It was one of my first builds too and technically it worked right away. As someone else mentioned, you need to line up the buttons with the faceplate carefully before soldering. I had a problem with two of my buttons getting stuck after being pressed, so I had to de-solder them and try again. Filing the hole may be quicker than messing around with a component that's already soldered on. Nothing difficult overall, but that's the one spot where you might need to spend more attention.
Robscorch
Not a complete bricking guess you could call it lock up, but either way a simple power reset fixes these chips apparently. I have bricked things, but usually it's just a chip replacement and maybe a few diodes and caps, but this is older stuff I have worked on which always needs tlc anyway to coax into functioning.
Silver
thanks everyone. Ordered the Penrose and will report back! wish me luck.
glennfin
I bought and finished the build on mine quite a while ago but only just got to powering it up and calibrating it last night. Disappointed to say the least. It locks up often, requiring a power re-cycle to bring it back, will sometimes produce slewing between notes, and other odd behavior, (trigger issues). Guess I need to try to load the latest firmware. meh
Altitude909
glennfin wrote:
I bought and finished the build on mine quite a while ago but only just got to powering it up and calibrating it last night. Disappointed to say the least. It locks up often, requiring a power re-cycle to bring it back, will sometimes produce slewing between notes, and other odd behavior, (trigger issues). Guess I need to try to load the latest firmware. meh


Sounds like you have other problems with it, i've never had one lock up
Zymos
Yeah, I doubt all that is a firmware issue...
glennfin
I see above, others have had issues with lock-ups and they seem to be related to firmware.. I have an older one so that may be the solution. Regarding the other issues I'm having, someone mentioned wrong value resistors, I'm going to put it on the bench and check every component.. confused


Altitude909 wrote:
glennfin wrote:
I bought and finished the build on mine quite a while ago but only just got to powering it up and calibrating it last night. Disappointed to say the least. It locks up often, requiring a power re-cycle to bring it back, will sometimes produce slewing between notes, and other odd behavior, (trigger issues). Guess I need to try to load the latest firmware. meh


Sounds like you have other problems with it, i've never had one lock up
bleeds_on_keys
Does anybody know if it would be at all possible to repanel this into MU? It's exactly what I want in a quantizer, except that it's not the right format. d'oh!
sonicwarrior
bleeds_on_keys wrote:
Does anybody know if it would be at all possible to repanel this into MU?

You can repanel anything into MU. The more relevant question is: How much can it cost?
bleeds_on_keys
sonicwarrior wrote:
bleeds_on_keys wrote:
Does anybody know if it would be at all possible to repanel this into MU?

You can repanel anything into MU. The more relevant quest is: How much can it cost?


Sweet, thanks for the help!
sonicwarrior
Btw. Analog Craftsman does that and is also located in Massachusetts, near Boston (Cambridge):
http://analogcraftsman.com/
bleeds_on_keys
sonicwarrior wrote:
Btw. Analog Craftsman does that and is also located in Massachusetts, near Boston (Cambridge):
http://analogcraftsman.com/


I am aware of Analog Craftsman, thank you! smile I had planned on contacting Tony when the time came to start this project.
L.C.O.
FetidEye wrote:
Dogma wrote:
im looking for a quantizer and Ive narrowed it down to this and the Uscale. Can someone tell me major plus and minus of the 2? Im sure Im not the only one asking this question.



penrose:
you can DIY this, for me this is a very good plus.
no menu's / hidden functions
clear interface, very playable

Uscale:
way more functions
less hp?


I would also like to add that Penrose auto-saves the current state (15 sec. after last change made), so that when you power down/up it will remember your user settings.

uScale does NOT do that. This is inexplicable to me, and probably single most annoying thing about uScale.
charonme
eeprom memory usually has lifespan on the order of 100 000 - 1000 000 write cycles, so if it automatically saved the state every minute, some of the modules would start to fail after ~2 years of running time (some even sooner)
pld
charonme wrote:
eeprom memory usually has lifespan on the order of 100 000 - 1000 000 write cycles, so if it automatically saved the state every minute, some of the modules would start to fail after ~2 years of running time (some even sooner)

Yes, assuming something changes every minute that needs saving and that the whole eeprom is re-written, but actual use time can be made much longer.
In this case, Penrose only saves if there was a change, only writes a small chunk and uses a simple wear-levelling to increase that about x128: thats about 35 years with 1000 saves per day source
L.C.O.
charonme wrote:
eeprom memory usually has lifespan on the order of 100 000 - 1000 000 write cycles, so if it automatically saved the state every minute, some of the modules would start to fail after ~2 years of running time (some even sooner)


what's your point?
no one is talking about saving things every minute.
teknobryan
I've noticed that when using a switch to go from my penrose to another quantizer (from my Rene) the pitch changes slightly. I think this is because C on my penrose isn't exactly 1V or 2V like it is on the Rene. How are you guys dealing with this? I don't think there's a way to shift down the C out of the Penrose.
bkessler
Hi all. I finished up my Penrose, and everything seemed to be working correctly, but when I started calibrating, I noticed the trimmer wasn't doing anything. I resoldered it and a couple of other places, then tried calibrating again. All was working well, then after a few minutes the trimmer stopped working again. Thoughts?
Boards below, and thanks!
bonjourmyfriends
teknobryan wrote:
I've noticed that when using a switch to go from my penrose to another quantizer (from my Rene) the pitch changes slightly. I think this is because C on my penrose isn't exactly 1V or 2V like it is on the Rene. How are you guys dealing with this? I don't think there's a way to shift down the C out of the Penrose.


There is no offset trimmer, but maybe you should try the regular calibration process if you haven't yet.

atte
Two questions regarding firmware:

1) I noticed there are two recent pull requests, both sound like must have fixes. Anyone tried them? And a friendly oneline crash course in getting these onto my computer (command line git on linux), tried google and I aparently was to stupid to follow the instuctions I found...

2) I have been meaning to try to implement quantize to closest note (penrose quantizes to first note below) and have some ideas on how to approach this. But before wasting my time, was anyone done this already?
bkessler
I fixed my issue (above)...there seems to have been a cold joint that I missed previously. Everything seems to be working as expected, but:

I just can't seem to get my Penrose calibrated properly.
If I follow the procedure outlined in the video and manual, I can get about two octaves to be perfectly in tune, but when I go higher, things start getting off (to the point where in one octave, the Penrose can't seem to decide what note to play if I have all the notes enabled).
I've tried with both channel 2 of MATHS and the BSP as voltage sources, and both Braids and Disting as oscillators. I've used three different tuners with frequency counters. I've tried calibrating from different starting points (both higher and lower frequencies), as well as using the 130/260 Hz example and musically in-tune notes such as A440 and A880. I feel like I must be missing something here. Maybe something is still wrong with my build?

Any ideas?
atte
bkessler wrote:

I just can't seem to get my Penrose calibrated properly.
If I follow the procedure outlined in the video and manual, I can get about two octaves to be perfectly in tune, but when I go higher, things start getting off (to the point where in one octave, the Penrose can't seem to decide what note to play if I have all the notes enabled).


I had problems with both my penroses, the input was off in the higher octaves. I made a simple change to the firmware, you could try installing it, and see if it helps (here with scaling 0.98, you might need another numbe to get it right through all octaves):

https://dl.dropboxusercontent.com/u/4343030/penrose_input_scale_0_98.w av
adh82
Hey gang,
I just built the pen rose and nothing was working when I plugged it in, then realised I had put the Transistor where the Voltage Regulator goes and vise versa. Oops d'oh!
So I swapped them back and it powered up but now 3 of the buttons won't turn off!
Did I fry somethings?
The gate out works and the input works but I can't seem to get a cv out.
Messed up chip maybe?
Any ideas?
adh82
Anyone?
Altitude909
adh82 wrote:
Hey gang,
I just built the pen rose and nothing was working when I plugged it in, then realised I had put the Transistor where the Voltage Regulator goes and vise versa. Oops d'oh!
So I swapped them back and it powered up but now 3 of the buttons won't turn off!
Did I fry somethings?
The gate out works and the input works but I can't seem to get a cv out.
Messed up chip maybe?
Any ideas?


That would put 12V on the uC and the DAC so yeah, you most likely fried everything
skellner
TechForze wrote:
Something went wrong...
Had a functioning Penrose, but lately I noticed the normal LED will lit at 50% strength and nothing more happening.
My fault for not getting some blind panels I guess.
Checked everything by eye and I don't see any fried parts or whatsoever.
help


Could you solve this one? I have the same problem. Worked fine, it took it out to check why some buttons are stuck and then it stopped working. Only D3 is on.
TechForze
Nope, I haven't fixed it yet.
Did you check if the top pcb touched the capicitator beneath it?
glennfin
bkessler wrote:
I fixed my issue (above)...there seems to have been a cold joint that I missed previously. Everything seems to be working as expected, but:

I just can't seem to get my Penrose calibrated properly.
If I follow the procedure outlined in the video and manual, I can get about two octaves to be perfectly in tune, but when I go higher, things start getting off (to the point where in one octave, the Penrose can't seem to decide what note to play if I have all the notes enabled).
I've tried with both channel 2 of MATHS and the BSP as voltage sources, and both Braids and Disting as oscillators. I've used three different tuners with frequency counters. I've tried calibrating from different starting points (both higher and lower frequencies), as well as using the 130/260 Hz example and musically in-tune notes such as A440 and A880. I feel like I must be missing something here. Maybe something is still wrong with my build?

Any ideas?


Had the same problems here a few months ago when I tried to calibrate.... put it aside hoping that a firmware update would fix it... getting ready to try again.. meh
oscarthesquirrel
glennfin wrote:
bkessler wrote:
I fixed my issue (above)...there seems to have been a cold joint that I missed previously. Everything seems to be working as expected, but:

I just can't seem to get my Penrose calibrated properly.
If I follow the procedure outlined in the video and manual, I can get about two octaves to be perfectly in tune, but when I go higher, things start getting off (to the point where in one octave, the Penrose can't seem to decide what note to play if I have all the notes enabled).
I've tried with both channel 2 of MATHS and the BSP as voltage sources, and both Braids and Disting as oscillators. I've used three different tuners with frequency counters. I've tried calibrating from different starting points (both higher and lower frequencies), as well as using the 130/260 Hz example and musically in-tune notes such as A440 and A880. I feel like I must be missing something here. Maybe something is still wrong with my build?

Any ideas?


Had the same problems here a few months ago when I tried to calibrate.... put it aside hoping that a firmware update would fix it... getting ready to try again.. meh


I've got 3 of them and same problem... moving up 2-3 octaves, the voltages are OK for 2, but then there's just no way of achieving the required voltages at higher octaves....
skellner
TechForze wrote:
Nope, I haven't fixed it yet.
Did you check if the top pcb touched the capicitator beneath it?


Yes, I checked that, all fine. The thing worked nicely before, so I think it's a bad solder joint. Will measure it through next week.
skellner
skellner wrote:
TechForze wrote:
Nope, I haven't fixed it yet.
Did you check if the top pcb touched the capicitator beneath it?


Yes, I checked that, all fine. The thing worked nicely before, so I think it's a bad solder joint. Will measure it through next week.


I finally fixed it by re-flashing the firmware with audio!
atte
I just bought two additional penroses (total of four), and after building the first of the two new ones a problem occurred: the Penrose is 20 cents sharp on lowest c. Since all the trimpot does AFAICT is adjust the slope of the v/Oct this means that if I follow the calibration procedure the quantizer will always be 20 cents sharp in all octaves. No problem if it was glues to an osc, but it doesn't really seems like the way it's supposed to be, right?

The other two are a about 5-10 cents flat, for some reason I never thought of it before, maybe because it's less pronounced on the first ones. I guess it's just a matter of tolerances on the components.

My question is: is there somewhere on the PCB, where it would be possible to solder a trimpot for adjusting the offset of 0V to actually be 0V
dschwabe
I bought a Penrose kit recently and just as I was about to start yesterday, I found that instead of the 6 1% 100k resistors the kit contains 5% tolerance once. Now I am worried that this may affect the tuning of the quantizer.
Should I play it safe and order 1% ones, or should I measure the ones I have and see what exactly their value is, potentially buying a bunch more of them to have more choices?

The other deviation from the instructions I found was a 220 Ohm instead of 221 Ohm resistor mentioned in the instructions (the BOM however also lists a 220 Ohm one).

I already contacted sonic potions but haven't heard back yet.
M-Circus
I just finished building a Penrose kit I bought from Thonk.

I'm having a weird issue. Everything lights up fine. In fairness I have one button that's slightly sticky, but it works fine when I take the panel off, so I guess I just have to make the hole a bit bigger. My main issue is that when I just pass audio through it, I'm getting major distortion on the output. I have zero idea where to start troubleshoot this.

Anyone on here have a clue what might be wrong? Gonna check over on the Sonic Potions forum too (as soon as I'm let in...), but thought I'd check with you first.

Marius
atte
You don't pass audio through it, it quantizes CV, which you can then send to an oscillator, making it only play the notes you selected on the mini keyboard on the panel.

Or am I missing something in what you try to do?
M-Circus
Hahahaha! Jesus Christ. There was indeed an early morning here with my three kids, but didn't think I was that tired...

Yes, I've used quantizers in the pass, so I know how they work. Total short circuit apparently. In my head... meh

Thanks. ;-)
echologist
M-Circus wrote:
Hahahaha! Jesus Christ. There was indeed an early morning here with my three kids, but didn't think I was that tired...

Yes, I've used quantizers in the pass, so I know how they work. Total short circuit apparently. In my head... meh

Thanks. ;-)
M-Circus
Hehe!
uncleyam
Are these out of production now?
needspeed
uncleyam wrote:
Are these out of production now?


I bought one a month ago, going to build tomorrow.

They show out of stock on full kit, but have PCBs and Panel, so I would contact them......Steve

You can find it here: https://www.sonic-potions.com/shop/index.php?route=product/product&pro duct_id=67
bovaflux
I saw him tweet that they'll be back in stock soon, he's just waiting on a PCB delivery.

https://twitter.com/sonicpotions/status/808972072168914944
kreiff
atte wrote:
Ok, here are the results of my highly unscientific tests:

All three DACs fared better than the one that came with the kit. One slightly better, one "above average" and one quite good. The two best ones are acceptable, the best is a keeper. I graded them (0-10): 2, 4, 6, 8.

With the original one most notes would be sharp or flat, about 10 notes as much as 30 cents. The best one has 95% of the notes below 5 cents, with a couple of by 10 cents.

For the test I used a BeatStep Pro, an orgone accumulator (but also A-110 and Z3000), a CED tuner and my computer based tuner.

For me this boils down this:

1) I'm now perfectly happy with my penrose, and will get a second one soon.

2) It pays off to buy additional DACs and select the best one, esp since they're only about a euro each.


Has anyone else tried Atte's DAC swap? What kind of results did you get?

I have two Penroses and one stays within 5-10 cents over 3 octaves - which I am fairly happy with, but the other is off by 15-30 cents into the 2nd octave.

I ordered some samples direct from Microchip Technology and I'm going to try 3 additional chips, but I was just wondering how much variance there is by chip and if others found that a small lot of 3 sample chips generally contains at least one "good" one.
kreiff
Got my MCP4801 samples on Friday and tested out the 3 chips they sent. It definitely seems like the accuracy is all over the place for these.

Of the 3 DACs I received one was excellent - between 5-7 cents off for 3 octaves. The 2nd was worse than the one that came with my kit.

The 3rd showed a very strange behavior. It was within 1 cent for 4 octaves just for C - but note-to-note (i.e. C#, D, E) it was off by 20 cents or more within the first octave. Not sure why that would be - as this wasn't the behavior I saw with any of the other chips.

I might see if they'll send me a 2nd batch of samples to see if I can get a chip for my 2nd Penrose that is good as the "excellent" one in the first sample pack.
atte
Good to hear! I ordered a second batch of 10, haven't found time to sift through them to find excellence yet hihi
ImNotDedYet
I'd like to purchase this kit and replace my Doepfer quantizer with the capabilities this has - particularly user-definable scales and playability.

It doesn't appear the kit is available anywhere in the US at the moment. I almost pulled the trigger ordering directly, but was warned of potential customs costs. I've purchased PCBs and panels as well as built modules that have cleared customs with no issues, but was wondering as this is a full kit if anyone encountered any customs issues with the kit when importing into the states?

Thanks.
Silver
I purchased it in the US and had no issues with customs.
I also have one fully built for sale/trade if you're interested, pm me!
Radical Ans
ImNotDedYet wrote:
I'd like to purchase this kit and replace my Doepfer quantizer with the capabilities this has - particularly user-definable scales and playability.

It doesn't appear the kit is available anywhere in the US at the moment. I almost pulled the trigger ordering directly, but was warned of potential customs costs. I've purchased PCBs and panels as well as built modules that have cleared customs with no issues, but was wondering as this is a full kit if anyone encountered any customs issues with the kit when importing into the states?

Thanks.


Same here. I was thinking of ordering direct as well.
kreiff
ImNotDedYet wrote:
I'd like to purchase this kit and replace my Doepfer quantizer with the capabilities this has - particularly user-definable scales and playability.

It doesn't appear the kit is available anywhere in the US at the moment. I almost pulled the trigger ordering directly, but was warned of potential customs costs. I've purchased PCBs and panels as well as built modules that have cleared customs with no issues, but was wondering as this is a full kit if anyone encountered any customs issues with the kit when importing into the states?

Thanks.


I've purchased two kits directly on two separate occasions and haven't incurred a customs fee. I've also ordered kits from Befaco and Thonk and haven't been charged a customs fee for those either. I wouldn't worry about it - just don't order 10 kits a once.
Radical Ans
Good to hear! Just pulled the trigger.

Question: Did anyone make any progress modifying the firmware for a 12-bit DAC? If not I may muck around w/ it when I get my kit. Got a few samples from Microchip coming in the mail soon.
BugBrand
ImNotDedYet wrote:
I'd like to purchase this kit and replace my Doepfer quantizer with the capabilities this has - particularly user-definable scales and playability.

It doesn't appear the kit is available anywhere in the US at the moment. I almost pulled the trigger ordering directly, but was warned of potential customs costs. I've purchased PCBs and panels as well as built modules that have cleared customs with no issues, but was wondering as this is a full kit if anyone encountered any customs issues with the kit when importing into the states?

Thanks.


There is now an $800 cutoff underwhich you shouldn't pay customs (since last year) - http://postandparcel.info/71740/news/new-800-us-customs-threshold-will -boost-cross-border-business/

& it is a cool kit for sure!
ImNotDedYet
Thanks for the responses!

I went ahead and pulled the trigger as well.

Looking forward to it!
Radical Ans
w00t! We're build buddies. Chugging Beers :
ImNotDedYet
LOL, I knew I liked you!
teknobryan
Is the output on this buffered? Basically can I send the output to several VCO's without a buffered multiple?
BugBrand
Yes, zero impedance output around IC U2A.
tappazee
I am the happy owner of a newly built penrose - it works great.

Could anyone tell me a way to use other modules to transpose the scale (e.g. transposing a Cmaj arpeggio programmed in to the penrose to a Dmaj arpeggio - emulating the root note shift function in the uscale, i think)? Is it a matter of running the penrose through a dc offset module? Or can a separate DC source just be added into the signal from the out of the penrose? Apologies in advance for n00b-ness.
ImNotDedYet
tappazee wrote:
I am the happy owner of a newly built penrose - it works great.

Could anyone tell me a way to use other modules to transpose the scale (e.g. transposing a Cmaj arpeggio programmed in to the penrose to a Dmaj arpeggio - emulating the root note shift function in the uscale, i think)? Is it a matter of running the penrose through a dc offset module? Or can a separate DC source just be added into the signal from the out of the penrose? Apologies in advance for n00b-ness.


Offset or better yet, a precision adder.
tappazee
[quote="ImNotDedYet"]
tappazee wrote:
I am the happy owner of a newly built penrose - it works great.

Offset or better yet, a precision adder.


Looks like precision adder is the way to go - thanks for the advice cool
ImNotDedYet
Just built mine. Great instructions - super easy build. Would be great for a beginner IMO.

Calibration was less painful than I expected. Seems to work very well for me. I don't have pitch perfect ears, but even through a couple of octaves I didn't get the nails on chalkboards feeling.

And thx for the Camel Balls! smile
Fierball
Hey all -

I ordered direct. Just received my (second) Penrose kit, and noticed that it came with an MCP4821 (12-bit), not the MCP4801 (8-bit).

Does that mean the new firmware uses the 12-bit DAC as standard? And more to the point, can I replace the MCP4801 (assuming I also upgrade firmware) on my old Penrose to make them the same?

Has anyone else received and finished building the new kit? Thoughts on performance? I'll certainly post my experiences, but it'll be a while yet as I have an o_C, and uBraids on the bench.

Thanks,
trockendock
Yup. Finished building mine tonight. Kit also came with the 4821 which threw me off a little. After not to much sleep i plugged it in this morning for calibration. It didn't really go that well. Two coffees and a whole lot of swear words later i realized that it shouldn't be fed with audio very frustrating after a halfass calibration it is now nicley quantizing my also newly built turing machine. I think i'll go sleep now hihi
zipzinc
Hello . I have built two Penrose Quantizers .I love them , They could be the perfect quantizers but the offset voltages are far too large ; 35mv and 60mv .
In my opinion offsets of more than 9mv make control voltages not usable for VCOs .
So I had to build two precision adders to reduce these offset voltages and add a new important feature : a transpose input . ( In my precision adders , the resistors are 01% matched )
Here is the schematic , it works the same way with eurorack +-12v
.




Radical Ans
Put mine together last night and am having some major issues. When I power it up it looks like the input is bouncing around all over the place (i.e. the red note LED is going up and down across the keys). I placed a scope at pin 1 of the MCP602 and saw the following trace when I had 0V patched to the input.



Looks like some kind of digital signal. Any ideas?

Edit: I should also note that the microcontroller appears to be working fine. I was able to put it into firmware update mode and send the latest firmware to the chip fine. The button LEDs also turn on and off with no issues when pressed.
Radical Ans
HUZZAH!!!

After some troubleshooting it looks like it ended up being some bad solder joints on the MCP602 socket. Seems to be working as expected now. I just need to do some calibration.
needspeed
I finished mine on Sunday after noting I was missing one freeking resistor. So as expected mouser came through for me and I powered her up and she worked right off the bat.

Missing the resistor was a good thing, as I must have checked the board 5 times in great detail ensuring every part was in the right place and all the soldering was correct. I like it as a good basic quantizer so far.......Steve
Michiel
Penrose has been difficult for a while now. It consistently shows an offset of ~1.3V at the output, compared with the input.

I check input and output voltages with the two channels of my O'Tool.
With all steps on the quantizer enabled the output voltage is 1.3V above the input. Really annoying...

I've done a fresh calibration, also checked the solder joints. My kit was bought direct from Sonic Potions about 2y-18m ago. Standard build - no changes to any of the resistors or caps.

Plenty of weird behaviour in this thread already, but haven't come across this particular problem. Any suggestions?
desolationjones
Does anyone have the schematic for Penrose? I'm trying to figure out if the LEDs are bipolar type.

I've been pondering a firmware tweak to add ascending/descending function for note selection. It would depend on being able to drive the green and red LEDs simultaneously to achieve yellow. Functionality could be:

Single short press: add note [green] or remove note [off] (as in current design)
Long press: add note to play ascending only [yellow]
Double-tap: add note to descending only [yellow]


@zipzinc that is a really cool addition you've made. Thanks for sharing the design with us.
mskala
The schematic is at http://www.sonic-potions.com/public/PenroseQuantizerSchematic.pdf - linked from the assembly guide. The LEDs are the two-wire type, so you can't drive red and green simultaneously. However, you don't need to drive them simultaneously. Blinking between red and green at a rate of at least a few tens of Hertz is good enough for human eyes to perceive it as yellow.
Radical Ans
Schematic can be found here: http://www.sonic-potions.com/public/PenroseQuantizerSchematic.pdf

I know because I had the same 1.3V issue and had to google around for the schematic a bunch.

My issue seemed to be bad solder joints on the U2 chip socket. For some reason the solder didn't adhere very well to it when I first built the module. I'd try and reflow all the joints on that socket and maybe some of the resistors associated w/ the 2 opamps on that chip (R3, R4, R5 etc).
desolationjones
Thanks! I'll look into blinking them instead. With that concept I could use PWM to have orange as a fourth color.

mskala wrote:
The schematic is at http://www.sonic-potions.com/public/PenroseQuantizerSchematic.pdf - linked from the assembly guide. The LEDs are the two-wire type, so you can't drive red and green simultaneously. However, you don't need to drive them simultaneously. Blinking between red and green at a rate of at least a few tens of Hertz is good enough for human eyes to perceive it as yellow.
kreiff
Fierball wrote:

I ordered direct. Just received my (second) Penrose kit, and noticed that it came with an MCP4821 (12-bit), not the MCP4801 (8-bit).

Does that mean the new firmware uses the 12-bit DAC as standard? And more to the point, can I replace the MCP4801 (assuming I also upgrade firmware) on my old Penrose to make them the same?


trockendock wrote:
Yup. Finished building mine tonight. Kit also came with the 4821 which threw me off a little.


Fierball & Trockendock - How is the performance with the 12bit DAC?

Fierball - Is there significantly better accuracy with the 12bit DAC over the 8 bit DAC in your original build with the new firmware?

I think I'll try updating mine with the new firmware and new DACs anyway - but wanted to hear people's opinions.
Michiel
Radical Ans wrote:
Schematic can be found here: http://www.sonic-potions.com/public/PenroseQuantizerSchematic.pdf

I know because I had the same 1.3V issue and had to google around for the schematic a bunch.

My issue seemed to be bad solder joints on the U2 chip socket. For some reason the solder didn't adhere very well to it when I first built the module. I'd try and reflow all the joints on that socket and maybe some of the resistors associated w/ the 2 opamps on that chip (R3, R4, R5 etc).


Thanks - solder joints on the chip sockets looked pretty good. Will try and reflow around U2... (may be a few weeks before I get round to it - will update).
Daisuk
Arrrr, good fucking grief I've been sloppy when building this, have just spent close to three hours filing down the bloody holes for the buttons because I soldered them without the panel on (misaligning them), and now one of the legs of the atmega chip just breaks off. Fucking hell! very frustrating Hopefully I can buy a new chip from Sonic Potions, as I have no fucking clue how to program those tiny things.

Could I potentially just get the code from Sonic Potions, get a new Atmega, and upload the code to the Atmega? And if so, how would you do that? Would something like the pickit2 work somehow, or what would you need to get the code from a computer to the chip?
Michiel
Michiel wrote:
Radical Ans wrote:
Schematic can be found here: http://www.sonic-potions.com/public/PenroseQuantizerSchematic.pdf

I know because I had the same 1.3V issue and had to google around for the schematic a bunch.

My issue seemed to be bad solder joints on the U2 chip socket. For some reason the solder didn't adhere very well to it when I first built the module. I'd try and reflow all the joints on that socket and maybe some of the resistors associated w/ the 2 opamps on that chip (R3, R4, R5 etc).


Thanks - solder joints on the chip sockets looked pretty good. Will try and reflow around U2... (may be a few weeks before I get round to it - will update).


Hey Radical Ans - thanks for the tip. I didn't really have any suspect solder joints - but I decided to reflow most of the two PCBs anyway. End result is that it now seems to work as intended. No more offsets.
Radical Ans
Michiel wrote:
Michiel wrote:
Radical Ans wrote:
Schematic can be found here: http://www.sonic-potions.com/public/PenroseQuantizerSchematic.pdf

I know because I had the same 1.3V issue and had to google around for the schematic a bunch.

My issue seemed to be bad solder joints on the U2 chip socket. For some reason the solder didn't adhere very well to it when I first built the module. I'd try and reflow all the joints on that socket and maybe some of the resistors associated w/ the 2 opamps on that chip (R3, R4, R5 etc).


Thanks - solder joints on the chip sockets looked pretty good. Will try and reflow around U2... (may be a few weeks before I get round to it - will update).


Hey Radical Ans - thanks for the tip. I didn't really have any suspect solder joints - but I decided to reflow most of the two PCBs anyway. End result is that it now seems to work as intended. No more offsets.


Glad to hear it! When I was troubleshooting everything seemed ok up until the output opamp so I figured it was something funky around that chip.
funkymogli
Hi, im having a problem with my penrose, its very unprecise..
its calibrated so a two octave jump is perfectly in tune, but if i just jump one octave is strangely 30 ct off, also the e (-30 ct) and other notes are randomly off a little, but enough to be really audible and make the whole thing useless for me.
the incoming voltage and the oscillator are very presice, with 7 octaves perfect tuning.


what are your expieriences? is that normal? what can be wrong?
thanks
atte
The firmware only uses 8bits of the DAC, so I think it's just impressions in the DAC you're seeking.

Supposedly there's a new firmware in the works that uses the 12bits of the DAC supplied with newer kits and implements a calibration procedure. Things should be much better with this in place.

Might not help much right now, I know...
Triglav
atte wrote:
Supposedly there's a new firmware in the works that uses the 12bits of the DAC supplied with newer kits and implements a calibration procedure. Things should be much better with this in place.


Do you have a source on that or is it just based on the fact that they've included the new DAC?
atte
Someone told me (hides)
Triglav
Cool, looking forward to it! Hopefully it also fixes the bug where the UI sometimes freezes if I'm clocking the trig in at high speeds.
technicoloraudio
just finished my penrose build and i was thrilled to see it light up when i plugged it in...

there is something going on with the buttons that is making them functionless. thye are all oriented properly on the board and i can start the module in firmware update mode and i did update the firmware, but bottom five white keys stay lit green and the top three black keys stay lit green with the exception of the top two keys alternating which is red.

i have checked every connection, polarity, and IC and everything seems to be in place.

anyone have any ideas?
Hezza11
I was wondering if anyone else has had this problem. Every so often my penrose seems to freak out and do a really fast ratchet. Its kind of like it can't decided between two notes so plays both really fast.

Happens about 20 secs into the below video, its just a simple turing machine output, through the penrose making plinky plonky on a Rings.

I've had it happen with other random CV sources so its not the turing machine.

Any thoughts? It its actually quite nice some times but I wouldn't mind knowing what causes it, think it was another minute or so before it did it again.

(sorry for the vertical video!)
eewee
Several people have noticed this as well, and if you look in the Sonic Potions forum, you'll find different solutions/workaround suggestions.

Here's one thread: http://forum.sonic-potions.com/discussion/725/penrose-erratic-quantiza tion

At least make sure you're running the latest (1.2) firmware.
Hezza11
eewee wrote:

At least make sure you're running the latest (1.2) firmware.


Thanks for the heads up. Just updated (not sure what I was previous running) but the problem remains. Although I did read on that forum post about using the trigger input which seems to have stopped it.

Someone did post a link to a fix they'd made in the firmware but the link is dead.
atte
A couple of weeks I spend a day with my four penroses, the 15 or so 8-bit dacs I ordered, my meter and a spredsheet. After a lot of measuring and swapping chips I now have all my penroses in tune in the range of +/- 3 cents with a few notes in the 7cents area. Super happy, huge improvement and totally worht the time spend.

It seems that some penroses were flat, some sharp, same with the dacs. So some that were like 20 cents sharp in one penrose made another penrose spot on.
lisa
I was looking for a quantizer that does exactly what I want and noting else and Penrose seems to fit the bill perfectly. A bit worrying though that so many of you have issues with it. confused
atte
If you solder it correctly, I think the main worry is tuning, which can be fixed by ordering 10 extra dacs and handpicking the best one...
lisa
Are there any Penrose user who hasn't experienced any issues? Who just built it and uses it with great success and happiness? w00t
mskala
One here. I haven't objectively tested how accurate the output on mine is; it sounds good enough to me.
amir
I just built one recently.. everything seems to work except when I plug anything into the trig in, the entire unit shorts out and the leds dim. I removed and replaced stuff and looked at the board more than I care to admit and there are no visible shorts. Either there is something wrong with the traces on the board or maybe one of the ICs but I haven't figured it out. To top things off I originally received a box of nothing but components too. Had to wait some time before I got the actual pcbs and panel from modularaddict.

side note, the only projects that I have had problems with have always been "kits". So much better buying your own components rather than getting them in a "kit" that has traded 50 hands by the time it arrives at your doorstep.
Hezza11
My build went ok and I use mine all the time, works fine apart from the occasional rachetting problem I posted about on the previous page. I tried updating the firmware but that hasn't helped, though using a trigger input fixes it so doing that now.
sammy123
I have two and both work well.
eewee
It was one of my first builds, so I had some trouble building it (somehow couldn't get the fuse to solder, and the wiggly buttons are a pain to get aligned and into the front panel).

But it works, as advertised :-)
Daisuk
eewee wrote:
It was one of my first builds, so I had some trouble building it (somehow couldn't get the fuse to solder, and the wiggly buttons are a pain to get aligned and into the front panel).

But it works, as advertised :-)


Yeah, agreed. A lot of build guides in general fail to mention the importance of mounting the faceplate before you solder the stuff that's supposed to stick up above it. I spent a good couple of hours filing down the holes of the Penrose to get the buttons to fit because I followed the build guide too pedantically.
juvation
has anyone done an upside down panel? i ask this because the regular orientation is a little weird... as the pitch goes up, the lights move down...

i built mine in an evening and it works fine, fwiw...
Swyndger
juvation wrote:
has anyone done an upside down panel? i ask this because the regular orientation is a little weird... as the pitch goes up, the lights move down...

i built mine in an evening and it works fine, fwiw...


Now, as you mentioned it wink ... I allways looked at the "keyboard", so it was obvisious, that the deep tones are on top. And most modules (like clock dividers) align the enelments on their panels to "start" at top.
There are more modules with scematic keyboards on the panel ...

http://www.doepfer.de/A1731.htm
https://www.modulargrid.net/e/addac-system-addac207-intuitive-quantize r-black
https://www.modulargrid.net/e/intellijel-%CE%BCscale-v2

... ok, it seems, that the deep tones are always on top. smile

OH, and by the way: My pentose does what it should sine I build it a half year ago, and soon I will build a second one. But I don't use the trigger out too often, so I can't be sure, that mine has no "racheting issue".
Vortico
Just a note if anyone has this problem in the future: one of the buttons couldn't fit through the machined hole in my panel so I had to drill it with a smaller bit to carve out the inside a fraction of a millimeter. Don't worry about being too rough with the drill. I applied quite a lot of force and there were no scratches is broken fragments on the panel.
eewee
also: the caps on the (beautiful!) buttons tend to wobble around a bit, so even if you do have the buttons aligned to the front panel, the moment you take off the panel, they tend to point away a bit in all directions. To then align them such that they fit the front panel again, is a task for the patient :-)
juvation
indeed, getting the front panel on is a challenge. in my case, one of the buttons wasn't 100% flush to the PCB, and so it would get caught under the panel and wouldn't return to its rest position. after resoldering the button (with the panel on, thankfully!) it was fine. phew!

so i would say, extra care with the button alignments... for when i build the second one...

i was going to get another in the Synthcube July 4 sale, but then i remembered that July is a no-buy month waah
niicholas
lisa wrote:
Are there any Penrose user who hasn't experienced any issues? Who just built it and uses it with great success and happiness? w00t


I built one, have experienced no issues, use it in almost every patch. If I remember correctly, aligning the panel with the jiggly buttons was a pain but I just used lots of masking tape to hold everything in place until soldered. w00t w00t
amir
Those that haven't had problems, can you list where you purchased yours and when? What firmware you are on (if you know) or if you've updated the firmware.

I have read others having my issue with the unit shorting when something is plugged into the trig in jack but nobody has ever posted how they fixed it. It is frustrating because this board is not super complicated and I've checked it a lot. Everything is in the right place and no visible shorts.

Also another thing that I have read that nobody has mentioned here yet is that it reacts differently to different cv inputs. Even when fully calibrated, it will work perfectly with some devices in the rack but then i'll plug in a midi to cv converter and it will start going nuts. I have checked that the other units are calibrated perfectly already and they work fine with everything else. The notes either go off by one semitone or lock with two notes on at the same time.
niicholas
amir wrote:
Those that haven't had problems, can you list where you purchased yours and when? What firmware you are on (if you know) or if you've updated the firmware.


I bought mine from Thonk in June 2016 & built it soon afterwards. No idea what firmware version; I've never updated it. This is fun!
eewee
same here - bought it at Thonk early 2016, and upgraded it to what I think is the latest software (1.2).
Swyndger
I've bought mine at the beginnig of the year in the sonic Potions shop ... Software? Don't know ...
basicbasic
amir wrote:
I just built one recently.. everything seems to work except when I plug anything into the trig in, the entire unit shorts out and the leds dim.


I have a similar issue with my Synthcube kit.

I can get it into the firmware update mode and that process seems to work but as soon as I plug cables in to CV or Trigger all LEDs go out.

Before I 'updated' the firmware I was just seeing the green LED being lit, none of the buttons.

I have checked the power rails - +-12 and 5v are all good. I have swapped out the TL072 for a known good one. I have beeped out continuity with a DMM and double checked all my joints.

I'm going to email Synthcube and see if they have any ideas - maybe the Atmega is knackered.
basicbasic
Ok, following this up in case it helps anyone else. I was able to flash a fresh Atmega and the Penrose now works.
eb0687
Need some guidance on how to flash a new Atmega microcontroller.

I have a kit with the included Atmega chip that I am yet to assemble. However, I am interested in the process of how to flash a new chip myself in case..

Thanks in advance for any suggestions.
Altitude909
eb0687 wrote:
Need some guidance on how to flash a new Atmega microcontroller.

I have a kit with the included Atmega chip that I am yet to assemble. However, I am interested in the process of how to flash a new chip myself in case..

Thanks in advance for any suggestions.


https://learn.adafruit.com/introducing-trinket/programming-with-avrdud e
eb0687
Altitude909 wrote:
eb0687 wrote:
Need some guidance on how to flash a new Atmega microcontroller.

I have a kit with the included Atmega chip that I am yet to assemble. However, I am interested in the process of how to flash a new chip myself in case..

Thanks in advance for any suggestions.


https://learn.adafruit.com/introducing-trinket/programming-with-avrdud e


Thanks for the link.
funky catsmell
I built one sometime last year and it's always worked nicely.

scaling is definitely a little wonky, though. i've repeatedly tried to match it to my yarns, and while it can stay close enough within a couple octaves, it trends either high or low on the extremes. no big deal, i assume it's down to component tolerances, and keep inputs within a limited range.

anyone else do anything with the gate output? i found it was resting at ~0.3v when "low", which is enough to read "high" on my logic modules, so i cut the trace and added a diode which solved the problem
antf4rm
tappazee wrote:
I am the happy owner of a newly built penrose - it works great.

Could anyone tell me a way to use other modules to transpose the scale (e.g. transposing a Cmaj arpeggio programmed in to the penrose to a Dmaj arpeggio - emulating the root note shift function in the uscale, i think)? Is it a matter of running the penrose through a dc offset module? Or can a separate DC source just be added into the signal from the out of the penrose? Apologies in advance for n00b-ness.


Add the root note to the output of the penrose with a unity gain mixer.
BRNDSCHTZN
I built this module a few weeks ago and actually I'm having some really weird behaviour...

When finishing my build I had some problems with it - but troubleshooting it I found out that I didn' had pushed the Atmega 168 deep enough in it's socket. After doing this I got a working module which finally I managed to calibrate aswell...

A few days ago I took out all the modules in my case to reasemble them newly and after doing so the Penrose is really behaving strange. All the LED's on the buttons are behaving as expected - they light up and I can turn them on and off but with CV coming through IN nothing is happening.

Yesterday I had the lower C note always active and no change when applying CV. I then measured the voltage on the OUT and measured 9,84 V there constantly. I also measured the IN and surprisingly got a voltage of -8,83 V there.

I dismounted the module but found no obvious problems when inspecting it. When I had the first problems directly after the build I already went through the build guide again and checked everything for correct placement and orientation as well as the solder joints...

Today I looked through this thread and the Sonic Potions forum but found no descriptions similar to my problem.

Before writing this post I checked the module again and got a slightly different behaviour now. A different note the C was active now, so again I made some measurements. I now measured 3,86 V on the out and -3,5 V on the in. When I plugged a cable to IN and just connected it randomly to a jack (for example from my RYO Ampmix) the voltage increased to 9,84 V and decreased again after unplugging the cable. In a second test I just made I had a voltage of about 5V with nothing plugged in and noticed that it was enough to raise this to nearly 10 V when just touching another jack in the rack with just the tip of a cable plugged to IN...

Any ideas how I could go on troubleshooting this strange problem?
batchas
BRNDSCHTZN wrote:
Any ideas how I could go on troubleshooting this strange problem?

To me it sounds like the power plug is shifted 1 pin, not aligning correctly +/GND/-
As you moved modules, the issue is maybe coming from the power connection of the Penrose. The way your power cable is plugged, I mean. Pers. I'd check again that the socket is correctly plugged on your module and in your case, aligning correctly the power pins. Sorry I can't find right now the correct english terms and need to go, but I hope you understand what I mean.

Or there's a bad power connection. It's a shame I can't remember how we call this grey band and the black plastic which connect module to bus in the case!

Check that the module does not touch the metal parts on your case too (ground issue).
I know it sounds silly, but it's worth a check before going deeper.
So I go now.
BRNDSCHTZN
Thanks batchas for giving me this hint!

Looking for a potential problem within the module I would have never thought about looking on this "other side"...

Unfortunately it doesn't fix my problem as there's everything fine with the connection. I also tried connecting the module to another ribbon cable and tested it with blank space on both sides to make sure there's no touching of the modules beneath it - all the time I get the same result (today the OUT was always near 10V no matter if a cable was connected to the IN)...
batchas
BRNDSCHTZN wrote:
ribbon cable

Ribbon cable d'oh!
Now I remember!

Hmmm... So it's not the power connection. S***
Was worth a check I think, but sorry it did not help much then.
I hope now someone who knows this module can help you fix it thumbs up
basicbasic
BRNDSCHTZN wrote:
(today the OUT was always near 10V no matter if a cable was connected to the IN)...


I had this particular symptom, and it was only resolved when I flashed a new Atmega with the firmware. Where did you get the kit from?
BRNDSCHTZN
Thanks for this information basicbasic!

I ordered the kit directly from Sonic Potions.

So maybe my next step will be to try flashing the firmware on this chip first and see what happens...
basicbasic
I ended up flashing a fresh chip and it worked. Was a huge pain in the arse getting the software set up but got there in the end. Perhaps SP could send you a new one?
BRNDSCHTZN
Hey basicbasic,

just a question to maybe clearify if we're really talking about the same issue here...

Did you read my earlier post about measuring a negative voltage in a similar range on the input?

BRNDSCHTZN wrote:
I then measured the voltage on the OUT and measured 9,84 V there constantly. I also measured the IN and surprisingly got a voltage of -8,83 V there.


Was this the case with your module aswell?

In my limitated beginner's understanding I was just wondering wether this negative-voltage-on-the-input-thing could really be because of the chip and the firmware?
basicbasic
I don't think I ever measured the input voltage but I was getting a steady ~10v on the output, but I did have other issues where plugging anything into IN or TRIG the module would seem to power off so it could be a different root issue.

Good luck, it's frustrating to be sure.

Maybe post clear photos of the top and bottom of the boards to see if we can help you spot anything.
Bottle
lisa wrote:
Are there any Penrose user who hasn't experienced any issues? Who just built it and uses it with great success and happiness? w00t

Yup, worked first time for me. Kit was purchased a couple of months ago from Thonk with (I assume) the latest firmware already flashed. Assembly wasn't difficult but then I've had plenty of kit-building and soldering experience so can't really comment on other users experiences. I'd say it was about as difficult as the Turing Machine. Maybe not suitable for a complete beginner as there are some fiddly bits but nothing major really.

I'm fairly fortunate that I have access to a well-equipped R&D lab at work so I had the use of a precision voltage source and a good quality scope, making the output calibration relatively painless (assuming the VCO on my 0-coast tracks 1V/oct accurately). Haven't put it though my various tuners yet for comparison, but seems to track well by ear, and that's the important bit TBH.

Ian
BRNDSCHTZN
OK - thanks again!

Think I will go on inspecting the module within the next days (as soon as I find motivation again)...

Maybe also looking at the schematic and mesuring for continuity between points. If anyone got some tipps what would be good to test beside power and ground connections (and in between for sure) - I really appreciate your help!

basicbasic wrote:
Maybe post clear photos of the top and bottom of the boards to see if we can help you spot anything.


...maybe I will do this - but first I have to find a decent camera and a place with enough light...
batchas
lisa wrote:
Are there any Penrose user who hasn't experienced any issues?

No issue as far as I can remember. It's in use in my Serge/BugBrand system.

EDIT: unfortunately it is now not true anymore since the last kit I bought a couple of weeks ago.
BRNDSCHTZN
...I continued in trying to troubleshoot my faulty module today.

I inspected the boards again especially checking for shorts in between solder joints and also measured cables plugged to the jacks for shorts. I also checked the power connector again. With all these test I got no unexpected results or found something looking suspicious...

Looking at the schematics didn't help me as an electronic noob to find other things I could measure.

Again I made some measurments with the module plugged into the rack. With nothing plugged into the input I got 9,8 Volts at the output and again a negative voltage of 8,8 Volts at the input. This measurements were made with all notes selected and the lowest one highligted in red as active. Then I found out that by disabling the active note the following note got active with the voltage at the output rising about 0.8 V whilst the negatve voltage at the Input was not affected. I could continue doing this for 8 notes with the voltage rising alway about approximately 0,8 volts but when I did the next step (from G to G#) the voltage at the output dropped to 0 volt. Continuing disabling notes from there again raised the voltage on the output for about 0.8 Volts but starting from 0V. All the time the mysterios voltage of 8,8 volts on the input was not affected. Putting a CV to the input didn't change anything at all...

Directly after building the module I had a strange behaviour similar to this. That time I also had a high voltage (about 7 V) at the output for the first 8 notes followed by a drop to zero with the next step. I didn't measure the input at that time but I think it was allright then as I could change the active note with CV. Troubleshooting the module I found that the Atmega chip was not pushed completely in its socket and by doing so it solved the problem and I had a working module which I could calibrate and use as expected...

So I removed the Chip again today and put it back making sure it is pushed into the socket correctly. I also measured continuity from the solder joints of the socket on the PCB to the legs of the pin and everything was allright there. Nevertheless powering up the module again gives me the same strange results. I'm really stuck here at the moment and have no idea what I could do as a next step to continue troubleshooting - so if there are any ideas concernig this I would be really happy!
workingklass0
Hello.

So, I recently finished building a DIY Penrose quantizer. Everything seems to be working fine, but there are three buttons that I am unable to switch off to change the pattern. The other buttons I am able to turn on and off with no problem just by pushing them.

I have calibrated the module and updated the firmware, but the problem still remains. Is there something I am missing?

Thanks.
deformative
workingklass0 wrote:
Hello.

So, I recently finished building a DIY Penrose quantizer. Everything seems to be working fine, but there are three buttons that I am unable to switch off to change the pattern. The other buttons I am able to turn on and off with no problem just by pushing them.

I have calibrated the module and updated the firmware, but the problem still remains. Is there something I am missing?

Thanks.


I had that same problem and the issue was the chip wasn't fully seated in the DIP socket. I felt like I was going to break something shoving it in all the way, but if you're using a socket that could be it.
AntonWoldhek
workingklass0 wrote:
Hello.

So, I recently finished building a DIY Penrose quantizer. Everything seems to be working fine, but there are three buttons that I am unable to switch off to change the pattern. The other buttons I am able to turn on and off with no problem just by pushing them.


check the soldering, reflow the points. I had a few that on first attempt didnt always react instantly, then when i just reflowed the solder a bit they worked fine.

Pretty easy build. My full kit from Thonk came with blue caps for the 18pF's instead of the ones marked with a red dot as indicated by the manual.
The manual suggests to solder the buttons before mounting the panel, I would humbly suggest the other way around.
workingklass0
deformative wrote:
I had that same problem and the issue was the chip wasn't fully seated in the DIP socket. I felt like I was going to break something shoving it in all the way, but if you're using a socket that could be it.

Which chip are you referring to? I know the long one (I forget the exact name of it) was difficult to get into the socket.
workingklass0
Alright, I finally got my Penrose working correctly. The problem: I forgot to solder one pin of the 2x8 female connector. very frustrating

Thanks for the help!
gnomenthusiast
Does anyone have a kit they'd be interested in selling?

There seems to be no option to get one at the moment, kits sold out, PCB + Panel sets are available, but the specific buttons used are not going to be available till June at least.

TIA
batchas
BRNDSCHTZN wrote:
I'm really stuck here at the moment and have no idea what I could do as a next step to continue troubleshooting - so if there are any ideas concernig this I would be really happy!

I had huge issues with the last kit I bought. Some components simply did not want to solder. Never seen this in all these years. I know you did already, but my advice is to check again every joint with magnifying glass and reflow if any doubt before you invest more time in troubleshooting the circuit and the different parts.
Check also the 2 electrolytic caps (100uF). In despite of my experience with soldering, I could not solder mine, and discorvered they had some kind of brown stuff on the legs, looked more like glue than corrosion, but no solder of any type wanted to take on these. So if you have a DWM check these first at their output.
Chek also the output of the 78L05. This one was also nearly impossible to solder on mine (nearly impossible means cold joint guaranteed because not enough surface for the solder to take).
batchas
gnomenthusiast wrote:
There seems to be no option to get one at the moment, kits sold out

I would wait a bit with this if I were you thumbs up
Silver
Hey Gang, I'm having a very weird problem with my Penrose. It seems to drop every fifth trigger or so. I tried to update the firmware last night, but kept getting a read error (I suspect because there is a problem with the trigger input). Any ideas what might be going on?

I can't imagine what sort of hardware issue would cause 4 triggers to work and then one not to register, so I assume it's a software issue, but I'm open to any ideas!!!

Thanks!
Silver
So I think I may have figured my issue out. I was using Batumi to drive the input and it seems that it's LFO range (0-10V) is hitting outside of some amount the Penrose can register, so when it's outside that range, the triggers don't work. That also explains why it was so consistent (LFO). When I tried a smaller and offset voltage range into the input, the triggers worked consistently.

I guess my "problem" is fixed now, but I'd be curious if anyone has the same problem using batumi with penrose, and also why exactly this is happening? The manual says Penrose should be able to take 0-10V in.

Thanks
guestt
Attempting to build one of these in Frac format, I tend to prefer visual instructions rather than text, so I worked out what I think the clues mean and made these photos, would someone be so kind as to confirm I have the wiring correct:





Thank you very much for your assistance smile
batchas
@Baddcr: I'll be able to help with the switch wiring and the rest in a few days when I'm back if nobody did earlier thumbs up
guestt
That would be very helpful batchas - thank you!

I am fairly confident, but confirmation from someone like yourself who has already done it would be very good.

In return and in the community spirit I will prepare documentation for the mod in full and share everything here so it is 100% clear and will help others doing this.
batchas
Baddcr wrote:
confirmation from someone like yourself who has already done it would be very good.

I see errors. So I'll give you the details very soon.
batchas
Baddcr wrote:
Attempting to build one of these in Frac format, I tend to prefer visual instructions rather than text, so I worked out what I think the clues mean and made these photos, would someone be so kind as to confirm I have the wiring correct

What I see on the picture you posted is that these should be wired like this.



Now about the switch if someone reads this:
It is needed for TRIG IN cause by replacing the 3.5mm plug with a banana we loose the normalization where output voltage will only change if a trigger is received.
As I don't have any magnifying glass anymore and totally blind to see anything behind my Penrose panel to help Baddcr and tell him how I did (here a good ex. which shows I should have noticed how I did on paper when I did it), I can't help him nor confirm the wiring he shows in his post is correct. Bummer.
I don't have the 3.5mm plugs neither which came with the kit, which would allow without magnifying glass to check which pins are used for normalization with my DVM.


@Baddcr: if nobody could help in a week or so, ask me again and I will take my module appart to see how I wired mine exactly.
guestt
Oh thank you!!!

I reviewed what I did and I actually got the assessment right, but drew it wrong on the photo d'oh!

Hehe, so funny as I spent ages checking and double checking that I understood the pinout on the sockets and their relationship to the pcb!

Anyway, definitely okay for the socket wiring, just the switch. I can't do it at the moment, but when I get chance I will write out my reasoning, and with a bit of lucky shouldn't have to take your module apart.

Thank you once again, I really appreciate your time and effort thumbs up
guestt
So, here's my rationale for the switch wiring, BugBrand posted this:

BugBrand wrote:
If I remember right - trig in goes direct in to the tip connection, but there is normalisation for the ring connector - when a mono plug is inserted, it connects to ground. I think I mentioned that in my banana bits a while back, no?

So - to clarify (just got your PM!) - tip goes to pin3 of J4, then you have a switch going from pin2 (ring) to pin5 (gnd)


The sockets that come with the kit have this pinout:



So my photo should be right:



pin2 could go to either end of the switch, depending on which way you wanted to flip the switch for normalisation. Perhaps to the right would be better thinking about it.

Cheers smile
batchas
I confirm thumbs up
Like Tom said.

Flu + time at home => I checked mine.
guestt
Oh wow - this is great - I like that this process is being documented so clearly!

Thank you very much indeed grin

thumbs up thumbs up thumbs up thumbs up thumbs up thumbs up thumbs up
guestt
Just finished this off, I can confirm that the voltage regulators are not needed, it works fine from 15V.

I didn't modify the PCB at all, I raised the buttons up from the PCB using the little pin holders from IC sockets that I broke up. This means the buttons are much higher out of the face panel and there's just enough room for the banana jacks and the wiring. It's really neat.

I used component legs to connect the banana sockets to the pcb - this means I could easily 'wire it up' by pushing the legs through the rather thin holes.

I used wire to connect the switch, made them slightly longer than needed so I could solder then assemble - made the process much easier!

The IC sockets for the upside down TL072 and the right way up MCP602 were a mistake and I had to desolder them so there was room. Next time I would mount both the TL072 and the MCP602 upside down and use sockets in both places - that's the only thing i am not 100% happy about with this build. The rest is good!

Hope this helps someone else making this conversion smile

Thank you to everyone who has helped - I really appreciate your input.
gbel
Hello,

I just started building the kit and while looking for the 100k resistors found out they were swapped to 99k's I know that in theory they are compatible `1%` band.

Is this a design change? If I have 100k's should I use them?

Please let me know.

Cheers!
HorseyWindpump
Just finished building mine, everything seems to work as it should after calibrating and updating to most recent firmware.

Except ... the green LEDs in the buttons seem very dim. Is this just me? I can hardly see whether they'e lit up or not during the daytime. Red seems a lot brighter.
funkytransport
lisa wrote:
Are there any Penrose user who hasn't experienced any issues? Who just built it and uses it with great success and happiness? w00t


Hey Lisa, I have built two and both work fine. (PCB, Panel and Chip from Thonk but sourced the other parts myself)

Cheers

Iain]

]
funkytransport
[quote="amir"]Those that haven't had problems, can you list where you purchased yours and when? What firmware you are on (if you know) or if you've updated the firmware.

Hey Amir.

I got my PCB, Panel and chip from Thonk, sourced the rest of the stuff myself. havnt flashed the ROM and it works fine from factory..

Iain
gbraakman
bensaddiction wrote:
This looks fantastic,

I'm just curious to hear peoples opinions on how easy it has been to calibrate?


Still, haven't succeeded in calibrating mine. If i understand correctly the red led indicates what the current incoming pitch is. the red led on mine is always in the same position whatever pitch/voltage i feed it. This makes calibration impossible.(?)
batchas
gbraakman wrote:
the red led on mine is always in the same position whatever pitch/voltage i feed it

Is it so as well when you have a few notes selected (green)?
pescatore
Finished building a Penrose last night and it seems to work great with one exception. The gate output always reads about 2.3V, even with nothing else patched. It then only gives a slightly higher pulse on note changes (haven't yet been able to measure the pulse voltage). Has anyone else seen this? I've gone over the boards carefully and don't see anything obviously wrong, joints look good, etc. Any ideas on where I might investigate? Thanks for any suggestions.
BugBrand
The circuitry is minimal - if you look at page 2 of the schematic you see that the gate signal passes through U3B (2nd half of IC 3). R2/R9 form a bias of 2.5V, then the rest is a unity gain inverter (using 10k resistors) - comes out to pin3 of the inter-board-header then straight out to LED and gate output --- ie. check around U3B! The resistors are 1k/10k/100k so check you haven't got any values muddled up.
pescatore
Thanks for the tips, I'll double check those resistor values.
sd_falter
What is the actual octave range of these modules? Can't seem to find a solid answer here.

From the manual you'd assume 10 octaves. (0-10v)

I built one recently and it seems to just crap out at the 6th octave and above

My test method:
Maths Output 2 to Penrose IN
OUT from Penrose to V/OCT on Plaits
Penrose only has the top button active
Slowly turn Maths 2 knob clockwise
Count the octave intervals monitored from Plaits.

First 5 octaves track pretty accurately, Octave 6 seems kinda flat and then any increases from that point the Penrose just seems to output a constant voltage.

I've noticed a few people in this thread mention they only seem to get about 5 octaves or so out of this module but never really seen confirmation if its an issue with their individual builds or this is expected behaviour..
BugBrand
Yes 0 to +10V.
I've been using the 12bit version of the DAC though haven't done deep comparison & can't remember offhand the part number!
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