Penrose Possibles (Open Source Sonic Potions Quantizer)
- chrisdermo
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BugBrand wrote:Just got the blessing from Julian!
AWWWWWW YE

WTB / WTTF: Bugbrand PRC2B, DD3, PRC4, ENV1
Current Bugs frame:
https://www.modulargrid.net/f/racks/view/580413
Current Bugs frame:
https://www.modulargrid.net/f/racks/view/580413
- rico loverde
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- Location: Portland, Oregon
- chrisdermo
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This is me raising my hand enthusiastically 

WTB / WTTF: Bugbrand PRC2B, DD3, PRC4, ENV1
Current Bugs frame:
https://www.modulargrid.net/f/racks/view/580413
Current Bugs frame:
https://www.modulargrid.net/f/racks/view/580413
- T. Jervell
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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?
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
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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

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

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 PhilBugBrand 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?
- BananaPlug
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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).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.
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!
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FS: KESAKO Player & Reverb for Serge and Buchla
FS: KESAKO Player & Reverb for Serge and Buchla
- DickMarker
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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.
Cool module btw - like what you've done with the design.
So this isn't my usual format haunt, but...
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.
FWIW there was some discussion on the (currently MIA) SP board about adding hysteresis to avoid the indecisive oscillation.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.
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

Ah, are you Patrick Dowling then? I did come across your firmware version and it did seem better than the original..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.
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..
Last edited by BugBrand on Mon Sep 16, 2019 3:50 am, edited 1 time in total.
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.
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.