[sdiy] That 2180 with modular cv??

dan snazelle subjectivity at hotmail.com
Tue Jun 28 03:22:37 CEST 2011

yes as i said , i was using a summing amp with a negative gain as per the demo circuit datasheet (a different sheet than the basic datasheet)

sorry if that wasnt clear

however it still thumped quite a bit

however I just found a circuit that might help !

check it out

(2150 is untrimmed version of 2180)


I am pretty sure someone out there is using the 2180's for vcas

i think there might even be a eurorack module that uses them

On Jun 27, 2011, at 8:54 PM, David G Dixon wrote:

> ... 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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