[sdiy] Multiplier vs VCA?

[TIm Daugard]

> I don't design in ANYTHING I don't have a full tube of... the design effort
costs way
> more than the worth of a chip you can't get easily / anymore...

I try to avoid the problem of expensive rare ICs. I have built a full system
(minus a keyboard and 1V / Octave VCO) using only opamps, transistors, and one
or two 555s. My system is an effects synthesizer for use with my bass.

After all most multipliers started as ring modulators, and most VCAs started as
three transistor balanced modulator with current drive to the third transistor
acting as an emitter resistor.

After saying that, my AD633s arrived yesterday. I looked at the spec sheet and
it says they need a minimum of 16 volts. My system is currently powered by a
regulated 12V. I'll have to check its response with filtered voltage only. I
have 16 to 17 volts feeding the regulator.

Tim (the bassman) Daugard