X-4046 VCO

Hmmm another VCO as well! Have tweeked in a couple of other oddities...

Mutant VCF

This is the almost stuffed Serge Mutant VCF -- it is an attempt to be a Serge VCF with voltage controlled Frequency, Resonance & Slope. Not really sure that having all three parameters Voltage tweekable will work but it is easy enough to drop back to just two, as in the originals... I have used That Coporation quad transistors for the gain cells in a hope that it will be both quieter and more stable than the original. I have also used silver mica capacitors in the analog path. Looks like and intersting filter, from reading a few reviews on the net. It's not like I really need another filter...

XFade Vactrol

Not the typical Buchla Vactrol but still seems to work OK...

XFade

Part of the Buchla Music Easel wavefolder clone. This is a VCA/Mixer that originally mixed between two wave shapes in the VCO. Here it has been just used as a VCA for a sinewave. The sawtooth used to modulate the signal gives a bit of an idea about the response but there is an enormous lag in the response time.

That's Spoilt it's Looks...

Found the problem with the Sync Circuit... the Transistor Array got some of it's pins changed along the way and whilst they are correct there is a special pin that is tied to the substrate... This is supposed to be at the lowest potential of all the transistors on the device... in theory... So we end up with this to get around some of those problems! We do now get s signal through to the output of the OTA and the transistor beyond... seems to get a bit lost after that though....

VCO Basket weaving...

The Sync circuitry on this thing has got knobs on it...