Hey everyone! I wanted to make the 3360 VCA and noticed the big ammount of buffering and mixing opamps and wanted to get ride of some of them. So in the pic shown below, I won’t use a CV knob for the VCA so could I possibly remove the first stage mixing opamp and directly plug the CV input on the buffer?
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No, because each of U1A and U1B is configured as an inverting amplifier, the first inverts the CV and the second re-inverts it to bring it back to its original state. If you omit the first one you end up with an inverted CV on the 3360. But I see no reason why you couldn’t omit both and replace them with a voltage follower:
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Aah yes I’m silly! It makes more sense now. I will use that opamp as a voltage follower and not an inverter thank you. And merry Christmas 
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Something I was curious about is the purpose of all the 100k resistors. Looking at the AS3360 schematic, 100k is definitely not prevalent. On the AS3340 VCO, Sam’s schematic varied slightly. Here, it seems to be a bit bigger of a change. Anyone able to help me understand this? Thanks!
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