Over the past 6 or 7 years I've been building a modular synth. It's a combination of both scratch built circuits and kits, and I have over (6) 3U cases full of modules. I currently have 5 Paia FracRak card cages and 1 Blacet rack. Unfortunately I have more modules than cases, so several are just sitting in a cardboard box right now.

In it's present state, it's a 3 oscillator synth, with various filters and modulation sources, a MIDI to CV converter, ring modulators, diode clippers, and a dedicated analog kick drum circuit.

As I mentioned above, I use FracRak cases. I chose to use 1/4" jacks for all audio and CV connections, and the modules use roughly 10v p-p signals. I have never gone back and really tweaked my I/O levels, although I probably should; some of my module's output levels are a bit high or low at the moment.

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This is a photo of my setup taken July 2004.

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Completed Module List:

Below is a list of all of the modules I have finished at this point. Click on the category names (VCO, VCF, LFO, etc) for more detail.

VCO:

• (3) VCO4D: EFM (based on Moog Prodigy)

VCF:

• (1) VCF-1A: Chris MacDonald SVF
• (1) VCF-2D: EFM (Moog ladder clone)
• (1) VCF-6C: EFM (EMS diode ladder clone)
• (1) VCF-8E: EFM (Korg MS-20 clone)

VCA:

• (1) VCA-1A: Scratch-built dual MS-20 VCA
• (1) VCA-2A: Scratch-built Thomas Henry VCA
• (1) VCA-3B: Scratch-built Dual Paia Fatman VCA
• (1) VCA-5B: EFM

EG:

• (2) ADSR-1A: EFM VC-RADSR
• (1) PEG-1A: Scratch-built dual Thomas Henry percussion EG

LFO:

• (1) LFO-1A: Scratch built dual Tri/Sqr (design by EFM)
• (1) LFO-2A: Scratch built 555 LFO (design by Moo Synth)
• (1) LFO-5A: EFM

CV Processors

• (1) PORTA-1A: Scratch-built dual Portamento

Mixers

• (1) MX2040: Blacet
• (1) MIX-1B: Scratch-built 5 channel stereo mixer

Logic

• (1) FD2040: Blacet Frequency Divider
• (1) GL-1A: Scratch-built AND/NAND or OR/NOR module

Waveshapers

• (1) RM-1A: Scratch-built AD633 Ring Modulator
• (1) RM-2A: Blacet Klangwerks Ring Modulator
• (1) DIST-1A: Racked Pro-Co Rat distortion pedal

Percussion

• (1) KD-1A: Midwest Analog Products ADV-Kick
• (1) DP-1A: Modified toy drum machine

Misc

• (1) 9700fr: Paia MIDI-CV converter
• (1) OCT-1A: Scratch-built octave swithcer
• (1) INV-1A: Scratch-built offset/invert module
• (2) Multis

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Unfinished Modules:

• (1) EFM VCF-2D
• (2) EFM VC(R)-ADSR
• (2) EFM VCA-6B
• (1) EFM LFO-5A
• (3) EFM KBD2E