See below for notes.


Dual VCO schematic - panel

Noise Generator schematic - Random Clocks schematic - panel

Dual AR Envelope generator schematic - panel

Dual Multiplier schematic - panel

DC Mixer schematic - panel

Triple LFO & Triple Sample/Track & Hold schematic - panel


Coming Soon:

Dual Composite VCA

Audio Mixer

Dual Instrumentation Amplifier

Dual Preamp/Follower


Dual State Variable VCF

Simple Sequencer

Full Wave Rectifier & Convolutors

..... and many many more!


I'm finally getting around to building my own modular synth.

I spent so much time designing and testing very fancy and complicated (expensive!)
modules, but never got around to actually building any of them.

For instance, the first VCO used a thermally heated matched pair (µa726), an LF356,
a high end chopper FET (2N4857), provided for ramp, pwm, triangle, sine, hard and soft sync,
linear FM, high frequency compensation for bulk emitter resistance in the exponential pair...

Too complicated. We used to have a lot of fun with an old Synthi AKS, which used to drift
all over the place. Time to reconsider.

I've designed this stuff with cheap albeit older parts, no specially matched transistors,
garden variety FETs, in other words, stuff on hand.

The panels are 4 x 10" hobby aluminum from K&S Engineering, available locally.

Forget etch primer, six coats of enamel, and silk screening. I'm lightly polishing
the panels with 00 steel wool, and applying a self adhesive laser printer transparency.

Stackable bannana plugs.

Please find attached the schematics, and some panel examples. All circuits have been breadboarded,
and are being built as shown, subject to small changes here and there.

Feel free to distribute freely, but please credit the author. Any comments appreciated!


Keith Daniel

Montreal Canada
December 2006