Cgs synth

A quick answer ....

>The first question concerns the statement "I also added 220K of series
>resistance to the FREQ knob." Does this mean in series with the resistive
>element of the pot, that is, between the pot and +15V? Or does this mean in
>series with the pot's wiper, that is, between the wiper and the CV pad on
>the PC board?

Probably the former. Otherwise it would make more sense to increase the
onboard resistor to 470k.

>The second question is, how should I add another pot to create the
>attenuated input? Should I just reproduce the FREQ pot and circuit shown on
>the schematic, but connect the "upper" end of the pot's element to the (new)
>input jack, rather than to +15V?

Exactly.

>Does the base of the transistor act as a summing node?

More like an "averaging" node than a summing node.

>Would I be better off using a simple op-amp summer to add the
>three control voltages and apply their sum to the base of the transistor
>instead?

Yes, but still keep the 220k in series with the base (i.e. use a CGS04
circuit, with its output fed into a CV input on the Steiner).


Ken
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Ken Stone sasami@... or sasami@...
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