Inspired by Polykit’s Pico DCO and just happened to spot a 3U rack case in my local electronics store yesterday I have embarked on a rack mount build of a polysynth.
2 DCOs per voice
Matrix 12 style filters with tracking/inverse EG etc.
Standard LFO with 16 waves
Dual ADSRs with looping and velocity
Noise source White/pink
999 patch memories
MIDI and USB input/output.
Got a bit further with this now, because I built a mux/DEMUX a few years back and later redesigned it for a project I was able to install this original one rather quickly into the synth. All pots and rotary switches are being read. I’ve yet to wire up the 12 push buttons and LEDs. Next is to remap all the controls properly into the mux/DEMUX.
Wait, so you started this 2 days ago ??? !!!
That looks amazing !
Actually started it Saturday evening, that pratially populated programmer board was already made and just need a little tweaking. The front panel is new.
Got the front panel installed, some tweaks needed for the dial positions but generally I’m happy with it.
You’re a machine! I need to get a move on…
Its looking great!
That looks amazing but you have no idea how depressing this is for lot of us… you are too fast…
It’s because I don’t have a job and can dick around all day on these things. When I was working a few years back my output was much slower.
All 12 voices (DCOs and modulation only) of the Polykit DUO installed and tested, had a little panic when the second card failed to startup. Seems I wired the detune CV to the run line instead of ADC1, that will stop your Pico dead in its tracks. Fixed that and diagnosed another 3 or 4 wiring faults and a 1M resistor where a 10k should have been. I added a midi router/merger to fix an issue with the Polykit design where it resides on channel 1 only, with this Arduino router I can select input to output channel and store in 10 user locations various configs.
Man, I’m buzzing with excitement for this.
I’m almost ready to test a filter board.
Nice !! I really like the light on the enveloppe slider !
So you are going to have a VCF per voice ?
I also have have one of this chip and I am planning on using it for my next project. Did you use the generic desgin ?
It will have all 6 filters when I receive my order of AS3372E chips that are currently lost in the post for a month.
Basically I’m using Polykit’s voice board filter design which seems to be almost identical to the matrix 12 implementation. I’m not using the panning currently but that could change. Also I’ve used Electric Druid Envgen8c chips instead of AS3310 chips as they are more microprocessor friendly. I also put back in the Matrix 12 pole switch so I have 16 variations and not 8. I can also feed velocity and keytracking in.
Good morning, I’ve managed to put together a github page with schematics for the filter boards/EG/LFOs/Noise etc and of course the programmer/mux/demux to make the synth programmable. Most of this is from memory and staring at the boards so I hope it works. Also a included is a block diagram of the synth. Shame to admit I have 4 processors in this box, one just to handle the MIDI.
This is so cool. Please post a lot of pics!
All of the pics are on the GitHub repository
Filter chips finally arrived to finish off the build. A small demo of sounds, programming is the hardest part. Now it’s polyphonic I’ve found some bugs in the portamento control I need to address but other than that I’m happy.
This is a triumph, something most can just dream of. It’s just wild!