The Poor Man's Memorymoog - adamstan's DIY Polysynth

via adamstan in this VSE thread. Be sure to check out the thread for follow up posts. The following is the first post in entirety. The reason why I captured it in entirety is so that we do not lose this. When I first started MATRIXSYNTH I linked to VSE threads only to find out they expired and dissapeared over time. That info is lost forever. That said, enjoy this one. It is pretty amazing. Be sure to listen to some of the sound samples below. I found this gem on Sequence 15.

"After almost 2 years of work, I've finished my DIY polysynth :D :D It is based on various module designs available on the net. I consider it to be a "Poor mans Memorymoog" with a little bit of Prophet 5 thrown in ;-). It features:
- 5 voices
- 2xVCO per voice
- 3xEG per voice (hardwired to pitch, cutoff and volume)
- 3xLFO (pitch, cutoff and PWM)
- Moog ladder VCF
- Noise source
- Ring Modulator
- Patch memory (128 user patches)
- MIDI
- Mono mode with selectable note priority (High/Low) and triggering (single/multi) and with portamento
- unison with adjustable detuning
VCO A offers sawtooth, square and triangle. VCO B offers sawtooth and square waves. Having triangle wave available is essential if you want to obtain some nice fm-like sounds from RingMod.

It's built using only standard off-the-shelf components - no CEM or SSM or similar chips inside - only typical opamps, switches, transistors etc.

Case (together with keyboard) was salvaged from some crappy 70's combo organ.

Here it is sitting on a stand (photo made with phone - sorry ):


With front panel lifted up:


With keyboard lifted up (showing voicecards):


Main digital board (keyboard scan, voice assignement and patch memory):


Voicecards close-up:


Front panel close-up [I love the rever keys for bass]:


MP3 demos


It is noisy and tuning drifts a little bit, but hey, isn't that what we love vintage synths for?"