Penrose Possibles (Open Source Sonic Potions Quantizer)

otoskope · Post by **otoskope** » Thu May 09, 2019 8:24 am

Oh, totally missed this thread. They look great, Tom. I hope you can make a batch, I'd definitely be interested.

BugBrand · Post by **BugBrand** » Thu May 09, 2019 8:48 am

Just got the blessing from Julian!

otoskope · Post by **otoskope** » Thu May 09, 2019 8:51 am

Great news!

chrisdermo · Post by **chrisdermo** » Thu May 09, 2019 10:50 am

BugBrand wrote:Just got the blessing from Julian!

AWWWWWW YE

anadeji · Post by **anadeji** » Thu May 09, 2019 3:33 pm

Very excited for this !

/\/\/\/ · Post by **/\/\/\/** » Thu May 09, 2019 10:17 pm

Always excited for new designs, but this one really gets the imagination going.
And that DC mixer built in ... great great great!

BugBrand · Post by **BugBrand** » Wed Sep 04, 2019 2:08 pm

Before rolling these out properly I'd like a few people to help as testers - ideally UK, but Europe would probably work too. I've got a few built so once confirmed things should get going fairly soon.

rico loverde · Post by **rico loverde** » Wed Sep 04, 2019 2:32 pm

BugBrand wrote:Before rolling these out properly I'd like a few people to help as testers - ideally UK, but Europe would probably work too. I've got a few built so once confirmed things should get going fairly soon.

excited for this one!

chrisdermo · Post by **chrisdermo** » Wed Sep 04, 2019 3:47 pm

This is me raising my hand enthusiastically

a100user · Post by **a100user** » Wed Sep 04, 2019 4:07 pm

happy to help if needed Tom as I have a vested interest in these becoming available, I want one

T. Jervell · Post by **T. Jervell** » Thu Sep 05, 2019 1:11 am

Guess I’m a bit late to the party... also not a UK resident...but still

But, very excited that the quantizer is near complete

sungja · Post by **sungja** » Thu Sep 05, 2019 5:12 am

I have the barton you did but this one looks more playable so put me down for one of these please.

sensanalog · Post by **sensanalog** » Thu Sep 05, 2019 1:00 pm

I so can't wait for this Tom!

Vcoadsr · Post by **Vcoadsr** » Fri Sep 06, 2019 12:24 am

Hi Tom, I'd happily do some testing for you, done my fair share of alpha & beta testing for Matthew at ALM over the years, cheers Phil

tIB · Post by **tIB** » Fri Sep 06, 2019 1:54 am

Always here if needed!

BugBrand · Post by **BugBrand** » Fri Sep 06, 2019 8:44 am

So, having had more of a check last night (+ help from Batchas) I wanted to mention the current issues. They appear to be based on the original design rather than my version as I've checked similar on my original 1FW Penrose adaption - as such, I'm not quite sure what to suggest.

1) Jittery behaviour - when using larger spans (3+ octaves) you can get some instances where the Penrose isn't quite sure which note to settle on, so you get trilly/jittery results. In my own usage I've tended to stick anyways to a few octaves, so I've not overly noticed this.

2) Crashes - This was flagged up by Batchas - I'd not come across it due to my usage, but I was finally able to replicate it repeatedly and also find that it occurred too on the original Penrose. As such I believe it might be firmware related. If the combination of CV ins and Initial are relatively high (I think summing to over 10V but haven't id'd exactly) then having an external trigger connected to the input (whether or not it is switched to use it) can cause the Penrose to latch up which then requires a power reset.

3) Accuracy - so I did move to the 12bit DAC but it is noticeable that these have some variance unit to unit. Mostly they seem pretty good, though I did have one testing yesterday which was really quite out just on the first octave. I guess I'll find out more through testing - might have to swap out some of the DACs if particular ones are inaccurate.

I've got a few built and flashed - shared one to another UK user, so hopefully there'll be further comments this weekend. Can equally share a few more around, but I'm still somewhat wary due to these points & that I'm unsure whether they can be sorted.

One point - I use an IDE programmer on these, but in theory you can use an audio file to update (haven't tested this yet). I'm not overly keen on sending loads out if users can't perform any firmware update.

Anyways - curious what people think?

T. Jervell · Post by **T. Jervell** » Fri Sep 06, 2019 8:57 am

Well, I guess you already know where I stand Tom

But regarding your point. Jittery/trill-behaviour I’ve experienced with more than three different euro quantizers, so I don’t know if this is a «common» problem that is hard to solve?
The crashing bit is of course unfortunate, but I guess as long as it’s know, and specific to what you just said then no problem.

So my opinion would to go for it. I don’t mind jitter/stutter, I’ve several times used it intentionally with my previous quantizers. But not all would agree with me, I know

otoskope · Post by **otoskope** » Fri Sep 06, 2019 5:10 pm

Well, you know my willingness to test things, Tom.... Looks like a great module, and I hope you get the issues sorted. I remember we discussed DC offset and attenuator already on the old dual Barton Quantizer. So useful!

Vcoadsr · Post by **Vcoadsr** » Sun Sep 15, 2019 1:38 am

BugBrand wrote: One point - I use an IDE programmer on these, but in theory you can use an audio file to update (haven't tested this yet). I'm not overly keen on sending loads out if users can't perform any firmware update.

Anyways - curious what people think?

Hi Tom, I’ve got a PICKIT 3 programmer that I use to update The Harvestman modules so if that’s what’s also needed to update the firmware on this then I can definitely help test - let me know what you think ... Cheers Phil

BananaPlug · Post by **BananaPlug** » Sun Sep 15, 2019 8:48 am

I wonder if this is a case where rigorous attention to grounding, bypassing, power filtering makes the difference even if no particular “cause” is discovered.

batchas · Post by **batchas** » Sun Sep 15, 2019 11:51 am

T. Jervell wrote:The crashing bit is of course unfortunate, but I guess as long as it’s know, and specific to what you just said then no problem.

It happened while testing (switching + increasing offset) but this kind of manip that brings it to crash is definitely not something I ever did in a "normal" situation when playing with the other Penrose(s).

Tom found out it's also on the original Penrose, which we did not know and it proves as said that it's really not a usual/normal manip!

DickMarker · Post by **DickMarker** » Sun Sep 15, 2019 4:53 pm

Just to chip in my twopence regarding jitter, every quantiser I've ever used has, when fed a wide cv range, been a little prone to jitter/trills as you described. So in that respect, it doesn't seem like something that necessarily needs correcting as it's to be expected and the key to avoiding it is in the hands of the user trimming the input to a usable range.
Cool module btw - like what you've done with the design.

pld · Post by **pld** » Mon Sep 16, 2019 1:36 am

So this isn't my usual format haunt, but...

BugBrand wrote:1) Jittery behaviour - when using larger spans (3+ octaves) you can get some instances where the Penrose isn't quite sure which note to settle on, so you get trilly/jittery results. In my own usage I've tended to stick anyways to a few octaves, so I've not overly noticed this.

FWIW there was some discussion on the (currently MIA) SP board about adding hysteresis to avoid the indecisive oscillation.
I know I implemented a naive version at some point (without looking deeper at the underlying adc resolution etc.) but then got distracted by other shiny things

I assume I kept the code somewhere though.

BugBrand · Post by **BugBrand** » Mon Sep 16, 2019 3:44 am

pld wrote:So this isn't my usual format haunt, but...

FWIW there was some discussion on the (currently MIA) SP board about adding hysteresis to avoid the indecisive oscillation.
I know I implemented a naive version at some point (without looking deeper at the underlying adc resolution etc.) but then got distracted by other shiny things :) I assume I kept the code somewhere though.

Ah, are you Patrick Dowling then? I did come across your firmware version and it did seem better than the original..
The strange thing remains that stability is good on for about 3 octaves - hardly any jittery behaviour.
I've not looked at code for ..years.. so unsure whether this project should be my route back in!

Edit - there's a github here: https://github.com/patrickdowling/Penrose

Yes, it is a shame that the Sonic Potions forum vanished..

BugBrand · Post by **BugBrand** » Mon Sep 16, 2019 3:48 am

So I didn't get much focus on this last week - hoping to move forward this week.

As mentioned above, the idea of delving into programming is not something I necessarily relish.

I have wondered about scaling everything down by a factor of 2 - I don't overly see the call for 10 octaves of range - 5 would seem more than enough. I'll have to have a check as to whether this reduces the potential for crashes etc. As mentioned it should reduce the scope of jittery behaviour and it does sound like for most users it wouldn't really alter usual usages.

MUFF WIGGLER

MUFF WIGGLER

Penrose Possibles (Open Source Sonic Potions Quantizer)