DX-style Operator (Thru-Zero FM/PM oscillator - FM Ogre)

From circuitbending to homebrew stompboxes & synths, keep the DIY spirit alive!

Moderators: lisa, luketeaford, Kent, Joe.

Post Reply
ubiquiphilia
Common Wiggler
Posts: 184
Joined: Mon Apr 14, 2014 5:41 am
Location: Tasmania

Post by ubiquiphilia » Mon Feb 22, 2016 8:59 pm

speaking of pin assignment, I'm looking at the fritzing schematic and board from the first post of this thread and trying to work out what AN0 through AN7 connect to; there's a list there "input buffers for each of: pitchknob, pitchjack etc". Is this order correct?

Also the unbuffered switch connectors and the led outs; which goes to what switch?

Cheers for you good work.

ubiquiphilia
Common Wiggler
Posts: 184
Joined: Mon Apr 14, 2014 5:41 am
Location: Tasmania

Post by ubiquiphilia » Mon Feb 22, 2016 9:03 pm

LED outs are self explanatory.

ubiquiphilia
Common Wiggler
Posts: 184
Joined: Mon Apr 14, 2014 5:41 am
Location: Tasmania

Post by ubiquiphilia » Mon Feb 22, 2016 9:29 pm

also outputs left/right are fm out ~ fm/pm out?

User avatar
wsy
Super Deluxe Wiggler
Posts: 2719
Joined: Wed Aug 24, 2011 10:20 pm
Location: near Boston Massachusetts USA

Post by wsy » Mon Feb 22, 2016 10:21 pm

ubiquiphilia wrote:speaking of pin assignment, I'm looking at the fritzing schematic and board from the first post of this thread and trying to work out what AN0 through AN7 connect to; there's a list there "input buffers for each of: pitchknob, pitchjack etc". Is this order correct?

Also the unbuffered switch connectors and the led outs; which goes to what switch?

Cheers for you good work.
Yes, in that order. in fact they're all "soft" meaning that there's a bunch of #define statements at the top of the program file
that say which AN goes to 1V/Octave, pitch knob, feedback knob, feedback jack... all that. So you can feel free to lay out your front
panel PCB any way you like and you can then "make it right" in the software.

- Bill
"Life is short. But we can always buy longer patch cords" - Savage

User avatar
wsy
Super Deluxe Wiggler
Posts: 2719
Joined: Wed Aug 24, 2011 10:20 pm
Location: near Boston Massachusetts USA

Post by wsy » Mon Feb 22, 2016 10:24 pm

wsy wrote:
ubiquiphilia wrote:speaking of pin assignment, I'm looking at the fritzing schematic and board from the first post of this thread and trying to work out what AN0 through AN7 connect to; there's a list there "input buffers for each of: pitchknob, pitchjack etc". Is this order correct?

Also the unbuffered switch connectors and the led outs; which goes to what switch?

Cheers for you good work.
Yes, in that order. in fact they're all "soft" meaning that there's a bunch of #define statements at the top of the program file
that say which AN goes to 1V/Octave, pitch knob, feedback knob, feedback jack... all that. So you can feel free to lay out your front
panel PCB any way you like and you can then "make it right" in the software.

In the DMAed version (recommended) it's not even that hard - the ADC is being fired autonomously by a timer, and the DMA channel is
continuously reading the output values and stuffing them into an array, so which one
is 1V/octave and which is the pitch knob
is just a matter of which cell in the array you read.

- Bill
"Life is short. But we can always buy longer patch cords" - Savage

ubiquiphilia
Common Wiggler
Posts: 184
Joined: Mon Apr 14, 2014 5:41 am
Location: Tasmania

Post by ubiquiphilia » Mon Feb 22, 2016 11:38 pm

ok well that's incredibly convenient.

Thanks for the quick answer Bill.

User avatar
wsy
Super Deluxe Wiggler
Posts: 2719
Joined: Wed Aug 24, 2011 10:20 pm
Location: near Boston Massachusetts USA

New version- narrower

Post by wsy » Thu Feb 25, 2016 6:56 pm

Okay, I did the layout for the new, narrower (and better!) version.

Changes: it's now laid out "PCB Frontpanel" friendly, using 0.100 connectors, at 6 HP wide! (the two rows of pins are 1" apart, perfect for
proto-boarding)

SYNC out is now a wide-swing signal (about -8 volts to +8 volts, no trouble triggering Serge and Buchla unlike before!). There's
a second "SYNClike" output, we'll figure out something for it to do to freak out the mundanes.

It has total and absolute reverse voltage protection. Power is derived via a bridge rectifier. And if you want to mod your software,
pin RB9 will be high if you have plugged the Doepfer cable in upside down. So, it can make rude comments out if you get the connector
in backwards. It'll use +5 for logic power if you got it, +12/+15 if you don't (settable by jummper. Doepfer and Dotcom power connectors
are overlapped on board.

Because the front panel is meant to be on another board, and there's complete freedom to move around (or duplicate) the 1V/octave inputs,
the analog ins are just expected to be +-5V and are self-protected. You can put your precision 1V/octave ins wherever you
want.... all analog ins use the same input structure, so pots go -5 to +5 and jacks should normal to -5V (or you can normal them to ground if
you want attenuverter action)

The license is now GPL V3. Send me money if you like. No requirement. Go forth and multiply.

Image

I moved around some stuff to make routing easier, so minor changes to the software (mostly just #defines in the header) will
probably be needed.
"Life is short. But we can always buy longer patch cords" - Savage

User avatar
Eloc
Wiggling with Experience
Posts: 497
Joined: Fri Jul 11, 2014 3:27 pm
Location: United Kingdom

Re: New version- narrower

Post by Eloc » Thu Feb 25, 2016 7:28 pm

wsy wrote:...Go forth and multiply...
I think you should edit the first post to contain a link to all the files/documentation, then they might multiply quicker... (I know that there's another thread with the relevant links in the first post, but it took me trawling through this thread to find that out.)

User avatar
wsy
Super Deluxe Wiggler
Posts: 2719
Joined: Wed Aug 24, 2011 10:20 pm
Location: near Boston Massachusetts USA

Re: New version- narrower

Post by wsy » Thu Feb 25, 2016 7:46 pm

Eloc wrote:
wsy wrote:...Go forth and multiply...
I think you should edit the first post to contain a link to all the files/documentation, then they might multiply quicker... (I know that there's another thread with the relevant links in the first post, but it took me trawling through this thread to find that out.)
Probably true. I'm going to play with the layout a little more, then send it to OshPark for fabrication.

In the meantime, if anyone would like to see the gerbers or the Fritzing file, I have been trying to attach it but it won't work.... aaugh! The
MW forum software won't accept a .fzz. So I'll pretend it's a .zip file and... viola!! Just rename the file deleting the ".zip" and it should open
just fine in Fritzing.

- Bill
You do not have the required permissions to view the files attached to this post.

User avatar
wsy
Super Deluxe Wiggler
Posts: 2719
Joined: Wed Aug 24, 2011 10:20 pm
Location: near Boston Massachusetts USA

Post by wsy » Sun Feb 28, 2016 1:36 pm

Oh- for those of you that can read schematics, here's the schematic of the new (narrow, 6HP) board.

Please let me know if you see any goofs. I'll be sending this off to OshPark in a few days, along with an MU frontpanel if I can get the
Switchcraft 112A jack layout into Fritzing.

Image
You do not have the required permissions to view the files attached to this post.
"Life is short. But we can always buy longer patch cords" - Savage

User avatar
burdij
Veteran Wiggler
Posts: 672
Joined: Mon Dec 28, 2009 4:38 pm
Location: Wisconsin US

Post by burdij » Sun Feb 28, 2016 6:24 pm

Here is how it turned out for me:

Image

This is based closely on the original schematic and will fit behind both an MU and Eurorack panel. The board is 4x1 3/4 inches.
Knobcon 7 - 2018 Photo Album
While website and store updates are in progress, access the Grove Audio Synth Store
Tesla Science Center http://www.teslasciencecenter.org

User avatar
wsy
Super Deluxe Wiggler
Posts: 2719
Joined: Wed Aug 24, 2011 10:20 pm
Location: near Boston Massachusetts USA

Post by wsy » Sun Feb 28, 2016 7:31 pm

burdij wrote:Here is how it turned out for me:

Image

This is based closely on the original schematic and will fit behind both an MU and Eurorack panel. The board is 4x1 3/4 inches.
Whoa!!!!!

I didn't realize you were that close to production!

When do you start selling these things?

- Bill
"Life is short. But we can always buy longer patch cords" - Savage

User avatar
burdij
Veteran Wiggler
Posts: 672
Joined: Mon Dec 28, 2009 4:38 pm
Location: Wisconsin US

Post by burdij » Mon Feb 29, 2016 11:21 am

I am working on a batch of 10 of these right now. They should be ready in about 3 weeks.
Knobcon 7 - 2018 Photo Album
While website and store updates are in progress, access the Grove Audio Synth Store
Tesla Science Center http://www.teslasciencecenter.org

User avatar
wsy
Super Deluxe Wiggler
Posts: 2719
Joined: Wed Aug 24, 2011 10:20 pm
Location: near Boston Massachusetts USA

Post by wsy » Mon Feb 29, 2016 3:51 pm

burdij wrote:I am working on a batch of 10 of these right now. They should be ready in about 3 weeks.
WOOO WOOO!!!

Are they pretty much interchangeable with the original ones? Because if so I will pick up some just as dev units for "extra Magic".

:trampoline: :trampoline:

- Bill
"Life is short. But we can always buy longer patch cords" - Savage

User avatar
synchromesh
Wiggling with Experience
Posts: 470
Joined: Wed Feb 09, 2011 5:30 am
Location: Norfolk, UK
Contact:

Post by synchromesh » Tue Apr 05, 2016 6:44 am

wsy wrote:[snip] I'll be sending this off to OshPark in a few days, along with an MU frontpanel if I can get the
Switchcraft 112A jack layout into Fritzing.
Hi wsy, how did you get on with your narrow layout? I have joined a Facebook group that is doing runs of open-source PCBs at (low) cost, and we're looking at the FM Ogre 'cause it's awesome. Would you like some more people to test your new layout?

User avatar
wsy
Super Deluxe Wiggler
Posts: 2719
Joined: Wed Aug 24, 2011 10:20 pm
Location: near Boston Massachusetts USA

Post by wsy » Tue Apr 05, 2016 9:44 am

synchromesh wrote:
wsy wrote:[snip] I'll be sending this off to OshPark in a few days, along with an MU frontpanel if I can get the
Switchcraft 112A jack layout into Fritzing.
Hi wsy, how did you get on with your narrow layout? I have joined a Facebook group that is doing runs of open-source PCBs at (low) cost, and we're looking at the FM Ogre 'cause it's awesome. Would you like some more people to test your new layout?
Layout's done, but I need to check it now.

Especially the voltage regulators - I need to nail down that I've got the pinouts right (for some reason, I never mess up op-amps but
I always mess up voltage regulators)

I actually worked on it some over the weekend. Then got sidetracked upgrading Fritzing. So no real "pointable-to-it" progress.

- Bill
"Life is short. But we can always buy longer patch cords" - Savage

User avatar
synchromesh
Wiggling with Experience
Posts: 470
Joined: Wed Feb 09, 2011 5:30 am
Location: Norfolk, UK
Contact:

Post by synchromesh » Tue Apr 05, 2016 10:09 am

Fair enough. We'd love to send you a couple of PCBs to say thanks, if we can get your design into the next run (due to close on April the 24th).

Cheers Bill! :tu:

User avatar
GryphonP3
Super Deluxe Wiggler
Posts: 1066
Joined: Tue Jan 29, 2013 3:20 pm
Location: Los Angeles

Post by GryphonP3 » Tue Apr 05, 2016 12:37 pm

Wow, that thing sounds phenomenal!! I would also be very interested in a PCB.. There are quite a few pages to read through here - has anybody tackled a PCB to distribute yet?
My cat can eat a whole watermelon ...

User avatar
wsy
Super Deluxe Wiggler
Posts: 2719
Joined: Wed Aug 24, 2011 10:20 pm
Location: near Boston Massachusetts USA

Power supply gone soft, causes twitch...

Post by wsy » Wed Apr 13, 2016 6:44 pm

I was looking at the scope and some waveforms coming out of an FM Operator... and I noticed a twitch.

Regularly. About every second... it would phaseshift about 5 degrees. Like the scope was triggering early.

But the trigger point was rock steady. Something was FMing the signal. Not that I could hear it, but I could _see_ it on the scope.

Which, to an EE, is really frakking annoying.

Oh crud. What's this then....

Noise? No.... even with a shorting plug, it's still there.

TWITCH beat beat beat TWITCH beat beat beat TWITCH beat beat beat....

So it's regular.... and then I look at the 4MS RCD/SCM and I see all the LEDs lighting up
with the same beat. Uh-oh.

Tap-tempoing the RCD/SCM slews the rate of the twitch. Double-plus uh-oh.

Turning the pulse width up and down changes the duration of the LED on time. And also the duration of the twitch. Okay... that
makes sense in a twisted, perverse way.

But still uh-oh. I pull the jumper to run the FM Operator off of the 5V supply instead of the +15 and TWITCH.... TWITCH... TWITCH.
So the 3V3 regulation to the DSP's analog section is not the issue.

I pull the RCD/SCM module out and unplug it. Twitch ...stops. Completely.

Now, this has me a bit befuddled because the only things that sit on the FM Operator's bus power without other regulation
are the input op-amp buffers - TL072's, which are seeing +-15 volts in the MU format and are supposed to have like 80 to 100 dB power
supply rejection.

Okay, learn something new every day. Dammit.... Fortunately, the next-generation board won't have this problem because it already
runs the rail-to-rail buffer op-amps from regulated 3V3, not from the frame bus direct without regulation. And the existing board
design will work just fine for most everyone who doesn't have crazy transient digital loads on their +15 bus line.

And unless you have a module with huge transient current draws (like the RCD / SCM which flashes 16 LEDs in synchrony at times) you will never see this issue.

And now I'm gonna move the RCD/SCM into a different rack frame. Maybe one with a stiffer power supply unit. (which might be
why when the RCD/SCM and the FM Operator shared power in the portable case, there wasn't a problem as that case has a
grossly overspecced switching power supply).

- Bill
"Life is short. But we can always buy longer patch cords" - Savage

User avatar
wsy
Super Deluxe Wiggler
Posts: 2719
Joined: Wed Aug 24, 2011 10:20 pm
Location: near Boston Massachusetts USA

Post by wsy » Sun Apr 24, 2016 8:15 pm

Okay, new narrow version is ready for final vettting and first prototype sendoff.

It will fit behind a 6U Eurorack. Yes, full functionality of TZFM Operator, in something the size of an Optomix. You can fit three of them in the space of one Maths, and have
space left over.

It is power-polarity-immune. It has both Doepfer and Dotcom power capability. It even
can run from +5 if it's available (move a jumper if you have +5). It does not have,
nor should it need the ugly heat sink.

Here's what it looks like:

Image

And here is the full Fritzing doc set. Iwill put them in the top of the topic when I have
debugged working units.

- Bill
You do not have the required permissions to view the files attached to this post.
"Life is short. But we can always buy longer patch cords" - Savage

User avatar
batchas
Super Deluxe Wiggler
Posts: 4654
Joined: Wed Nov 09, 2011 2:51 pm

Post by batchas » Mon Apr 25, 2016 4:37 am

wsy wrote:Okay, new narrow version is ready for final vettting and first prototype sendoff.

It will fit behind a 6U Eurorack. Yes, full functionality of TZFM Operator, in something the size of an Optomix. You can fit three of them in the space of one Maths, and have
space left over.

It is power-polarity-immune. It has both Doepfer and Dotcom power capability. It even can run from +5 if it's available (move a jumper if you have +5). It does not have, nor should it need the ugly heat sink.
Awesome :sb:
-----------------------------------
Batchas website
Bandcamp page

User avatar
bezier
Wiggling with Experience
Posts: 306
Joined: Tue Jan 29, 2013 5:48 pm
Location: berlin

Post by bezier » Mon Apr 25, 2016 5:07 am

really cool wsy, thanks a lot :guinness:

TimoRozendal
Wiggling with Experience
Posts: 386
Joined: Fri Dec 12, 2014 8:03 am
Location: Netherlands

Post by TimoRozendal » Tue Apr 26, 2016 2:02 pm

awesome wsy!!

I am puzzling with what connections you have for in and out and that they mean with the latest firmware. Sorry if I missed some info and ask things double.

Is the latest firmware the FMOgre_DMA_Main.c? or perhaps this latest pcb version needs some tweaks to work?
are all analog inputs +-5v including the knobs?

Here are the lists of input and ouputs and what I think they mean

S1 LFO switch, latching, will choose range of module
S2 Resolution switch, latching, will reduce bitrate?
S3 Sample switch, latching, will enable sampling of input and use that as source instead of sine table, which input is sampled? the feedback jack input?
A0 exponential pitch jack, V/Oct,
A1 operator feedback jack,
A2 freq mod jack
A3 phase mod jack
A4 phase mod index knob
A5 fm mod index knob
A6 operator feedback knob
A7 pitch knob
D1 Sync input?

O1, RC4 ?? sync out?
O2, RC5 ?? sync out? an extra output?
L1 led to indicate 'heartbeat', indication of frequency?
L2 led to indicate if frequency is negative
L3 led to indicate if phase is negative
Le, DAC1LN ?? FM or PhaseMod output?
Ri, DAC1RN ?? FM or PhaseMod output?

btw, DAC1RP is mentioned in firmware as primary out, but does not appear to be connected
and RB8 is sync out in firmware, but also doesn't seem to be connected in this version

thanks!

User avatar
wsy
Super Deluxe Wiggler
Posts: 2719
Joined: Wed Aug 24, 2011 10:20 pm
Location: near Boston Massachusetts USA

Post by wsy » Tue Apr 26, 2016 3:16 pm

TimoRozendal wrote:awesome wsy!!

I am puzzling with what connections you have for in and out and that they mean with the latest firmware. Sorry if I missed some info and ask things double.

Is the latest firmware the FMOgre_DMA_Main.c? or perhaps this latest pcb version needs some tweaks to work?
are all analog inputs +-5v including the knobs?

Here are the lists of input and ouputs and what I think they mean

S1 LFO switch, latching, will choose range of module
S2 Resolution switch, latching, will reduce bitrate?
S3 Sample switch, latching, will enable sampling of input and use that as source instead of sine table, which input is sampled? the feedback jack input?
A0 exponential pitch jack, V/Oct,
A1 operator feedback jack,
A2 freq mod jack
A3 phase mod jack
A4 phase mod index knob
A5 fm mod index knob
A6 operator feedback knob
A7 pitch knob
D1 Sync input?

O1, RC4 ?? sync out?
O2, RC5 ?? sync out? an extra output?
L1 led to indicate 'heartbeat', indication of frequency?
L2 led to indicate if frequency is negative
L3 led to indicate if phase is negative
Le, DAC1LN ?? FM or PhaseMod output?
Ri, DAC1RN ?? FM or PhaseMod output?

btw, DAC1RP is mentioned in firmware as primary out, but does not appear to be connected
and RB8 is sync out in firmware, but also doesn't seem to be connected in this version

thanks!
You have it pretty much correct!

Everything on the inputs is now designed to expect and scale +-5 volts, with overvolt/undervolt
protection, including the knobs. That way, you can put jacks and pots any which way
you like (unlike the old design that had voltage protection only on the four jack inputs.
That's why the "input" side also has +-5V available, to make it easy to feed the pots.

You *might* have S2 and S3 switched around.

D1 is indeed Sync In / Freeze In. It has a weak (1 Megohm) pulldown to ground.

O1 is indeed Sync Out (which is still a bit funky, as the hardware antialiasing causes
the analog outs to lag slightly).

O2 is for future expansion. :-)

DAC1RP and DAC1LP are the left and right differential pair positive outs. But there's an
inverting output buffer following them, so using DAC1RN and DAC1LN instead yield
"correct-polarity" outputs. It's a trivial change that doesn't modify the software
at all.

RC4 is indeed the new Sync Out. That's because it was getting too crowded to route a line
into the buffer area from the old position up in the northwest of the DSP. I may
reevaluate that though as it's the one truly incompatible change in the software, and now
there may be room after all since I replaced the +-5V regulators with SOT2-3 packaged ones.

Also, if you have the schematic, take a look at RB9 (pin 1) and what it lets the DSP
sense. Trust me, hilarity will ensue. :-)

- Bill
"Life is short. But we can always buy longer patch cords" - Savage

TimoRozendal
Wiggling with Experience
Posts: 386
Joined: Fri Dec 12, 2014 8:03 am
Location: Netherlands

Post by TimoRozendal » Tue Apr 26, 2016 3:40 pm

thanks Bill for the quick reply and all the info!
I will chew on it :-)

@RB9 haha.. nice.. since you use 4 diodes to get the correct polarity you can use this to unlock the easter egg :-)

Post Reply

Return to “Music Tech DIY”