This is a Korg X-911 that I have re-built to a modular synth.
The original X-911 Guitar Synth actually contains much more than is obvious on the front panel:
1 pre-amp, dist unit, P-V converter and envelope follower/trig detector
1 multi-waveform, multi-octave output MS-20-style VCO with both lin and log CV
1 MS-20-style VCF
3 MS-10-style VCF:s (discrete KORG35) used by the Bass, Tuba and Trumpet presets.
9 simple EG:s
I have made most of these modules accessable at the front panel and layed out like a modular synth.
The synth is then packed into a chassis that fits nicely in my MS-rack.
The modules are pre-patched like the original 911. VCF 3 and 4 also have a LPF/HPF switch. The modules are:
1 x External Signal Processor: Input level, Range, Portamento knobs. Input, Dist out, Env out, Trig out, Hz/V out jacks.
1 x VCO: Octave, Coarse, Fine, CV1, CV2, 8" PWM, 16" PWM knobs. Hz/V, V/oct, CV1, CV2, 8" PWM, 16" PWM inputs,
16" sqr, saw, pulse, 8" sqr, saw, pulse, 4" sqr, saw output jacks.
4 x VCF: Cutoff, Resonance and Env CV knobs. LPF/HPF switch on VCF 3 and 4. Input, output, Env and CV jacks.
2 x Active filter: Tone knob, Input and output jacks.
6 X VCA: Input and output jacks.
2 x AR Envelope: Attack and Release knobs, Trig in, output jacks.
3 x D Envelope: Decay knob, Trig in, ouput jacks.
1 x 8 input mixer: Level knobs, input jacks.
1 x Output module/VCA: Volume and CV knobs, CV in and ouput jacks.