Analog Synth

The biggest electronic project I ever did. Actually, I started in 1980 but couldn't make the pcbs then. Retried in 2000, and this time I didn't give up...
There will be detailed descriptions and schematics of the modules as soon as I have the time.
The beginning. I'd like to add an article about the making of PCBs... (some day)
The basic rack and the power supply.
Rear view. You can see the transformer, the master volume pot, mute switch and the headphone jack.
From now on you can call it a synth: In/Out panel, oscillator #1, test keyboard; the module in front is an ADSR envelope plus a exponential VCA.
Same as above with the ADSR/VCA built in and a beautiful red trigger switch in front.
The filter. On the right side of the board you can see the famous transistor ladder (thank you, B.M.!), on the left there is another ADSR.
The filter is in. But will it work?
My workbench. Just testing the filter module.
Basic synth with 1 oscillator, 1 filter, 1 VCA and two envelopes.
Rear view, with connections to the patch bay.
Oscillator #2
The mixer and the ring modulator, plus an envelope follower for the external input.
Growing. Still some space in there.
Different point of view.
Needs a bigger power supply. The 3 oscillator chip heatings are eating all the current.
The bigger transformer causes hum in the VCA. Built an external power supply.
What to do with the empty space: Two separate 4-stage frequency dividers and fixed filter banks, two additional LFOs and linear VCAs.
Front view of upper rack. 70's organ switches for frequency dividers and fixed filters.
OK. I did my best to put in as much as possible.
Nice photo for the brochure, huh?
Indispensable needful things.
More I.N.T. Also see The Moog Archives (menu "Oddities")