VCAs v. Attenuators

Not strictly about any individual plugin or module, but more of a conceptual question.

What difference is there (if any) between a VCA and an attenuator, philosophical or otherwise?

When I was initially learning synthesis years ago, I learned that VCA was an initialism for “voltage controlled amplifier,” but the more I watch and learn about modular synthesis, I’m finding that many people use VCAs in a way similar to what I would consider to be the job of an attenuator, though I guess most can be made to do the same things when there’s no actual “amplification” happening.

So in the [virtual] modular world, is there any functional difference between an attenuator and a VCA module? What makes a module one or the other aside from the name?

An attenuator doesn’t need to have a CV input. A VCA doesn’t need to have a knob. If a module has both, it is both a VCA and an attenuator.
But both apply output = input * gain, where gain is either the knob position (from 0 to 1) or the (nonnegative) CV input.

6 Likes