[sdiy] That 2180 with modular cv??

David G Dixon dixon at mail.ubc.ca
Tue Jun 28 02:54:18 CEST 2011

... or, of course, you could use just the one summing amp at a max gain of
0.2, and use the other pin.

> The datasheet says that the control pins are to be limited to 
> +/-1V.  If you feed an undivided gate or envelope signal to 
> the control pin, the VCA will clip hard.  I would sum a CV 
> attenuator pot and a CV bias pot (the latter injecting 
> voltages from 0 to 5V into the summing node) pots to convert 
> any control signal (e.g., 0/+5V, 0/+10V, or -5/+5V) to 0/-5V, 
> and then invert the result at a gain factor of 0.2 to 0/1V 
> and use the circuit in Figure 2.
> I'm not sure whether you'd want to use the Ec+ pin or the Ec- 
> pin (I haven't looked at it that closely -- in either case, 
> the unused one is grounded), but the main point is that the 
> THAT 2180 is about 5 or 6 times more sensitive to control 
> voltage than the SSM2164.

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