Voltage Controlled Crossfader/VCA

[Thomas_Henry]

Hi Gang,

As promised, here is another circuit for you to play with. It can be used either as a voltage controlled crossfader or as an ordinary VCA. I hit upon this when finally realizing something that was in front of me all the time---the control currents though the voltage-to-current converter are symmetric yet opposite. It's an obvious idea once you see it and has probably been used before. But I was glad to stumble upon it.

Null out the DC thumps in the usual way. (Turn the audio inputs down, then apply a 0 to +5V square wave to the CV input.)

The usual legalese applies. Feel free to use this for personal applications but don't copy, or produce commercially. Anyone wanting to do a non-commercial PCB for EM users please contact me first.

Have fun!

Thomas Henry

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[v-un-v]

Looks fun Mr Henry! Cheers!

[inlifeindeath]

can't wait to try out the new designs thomas! thanks as always for your work!

[widdly]

Thanks for another great design Thomas.

I built it this afternoon on perf board and it works very nicely. Like the other TH designs I've built, the input ranges on all the controls are tuned perfectly.