homemade polysynth

https://github.com/minisystem/System-100-PS22-PS24

Just brought an early Oberheim SEM back to life. The pot that sweeps the filter type had failed and upon disassembly it was apparent the resistive track had completely disintegrated. It has a built-in switch for bandpass mode, so finding a replacement seemed impossible. I took a tip from this site and found a CTS donor pot. The phenolic board with the resistive track mounted on it is the same shape as the original one so it can be swapped.  I couldn't easily obtain the PCB pin type but was able to improvise with the solder lug version, which is readily available from Digikey (ignore the Digikey photo, it incorrectly shows the switch version). 

About as tidy as it gets.

Panel design nearing completion. #eurorack #tr808 #808 #drummachine #inkscape #opensource

Playing well together. #korg #sq1 #sdd3000 #delay #roland #system500 #eurorack #tr808 #808

Eurorack TR-808 gets a sequencer

MIDI sequencing of Eurorack TR-808 clone. Toms and Congas and Rim Shot/Claves switched electronically, allowing dynamic assignment in the same sequence.

MIDI sequencing enabled. #eurorack #808 #tr808 #drummachine #congas

http://system79.com/korg_volca_beats_snare.html

TR-808 Start/Stop button replacement with new Cherry MX switch assembly. #tr808 #cherrymx #3dprinting

Makes noise. Analog voice card test bed. #eurorack

DDR3 240 DIMM format analog voice card in test bed. 2VCO, VCF, VCA, 2ADSR. #polysynth #synth #analog

Software to hardware. #kicad

Polysynth voice card oscillator FM test. #polysynth #eurorack #synth #analog #sq1 #korg

Starting work on new module inspired by a classic but -ring mod, +slew #eurorack #system100m #lfo

First 3D view of main board and step switch board assembly. #eurorack #tr808 #kicad #freecad #drummachine