VCA CV input on R55

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EPTC
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VCA CV input on R55

Post by EPTC » Sat Oct 13, 2018 3:48 pm

Hey there, Can anyone explain how the VCA CV input on the R55 works?

I've tried a variety of CV sources but not sure what happens with that. Is it a gate? Do you send it a pulse or an envelope?

Love the R55, of course. The things snarls. Just curious about options to try with that input.
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Post by metasonix » Sat Oct 13, 2018 5:26 pm

Um, manual? Don't have a copy?
The VCA CV INPUT may be used to control the output level of the R-55, as with a standard VCA. Note that the R-55 will produce maximum gain with nothing plugged into this input. The CV used on this input will completely cut off the R-55 signal when -4 volts is applied, and give a moderate signal output with 0.0 volts. So, if full control over the gain is needed, as with an envelope generator, a negative offset will have to be added to the EG's output. This may be done with a module such as the MalekkoTM 8NU8R or Doepfer A183-2.
it can also be used for voltage control of clipping by adjusting the OVERDRIVE LEVEL appropriately.

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Post by EPTC » Sun Oct 14, 2018 1:22 pm

Ha, how could I have missed that when I originally RTFM'd!

I think I'd tried something some time before but hadn't noticed any change, so was uncertain what CV to feed it. (Back then I was still trying to figure out Hz/v with the osc itself) But man, going at it with intent today just spent the happiest hour of the weekend sending different CV into that VCA input. Totally expands what is already my favorite VCO. How awesome.
metasonix wrote:it can also be used for voltage control of clipping by adjusting the OVERDRIVE LEVEL appropriately.
Hot dog, yes! Got that to work and then paired the same VCA pulse with the R51 with just a touch of offset so they're out of sync. Wow!

Beautiful, thanks Eric.
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