Open letter

[Sean Costello]

Paul Perry wrote:

> And what is more mystifying, is why nobody made a state variable filter with a
> multiplier as the active voltage control element. I think the technology
> was aroundat the time, in analog computers.

Besides the EML synths Terry Michaels mentioned, there was a circuit
based on this principle in one of the early Electronotes (i.e. around
#14 or so). At some point, Electronotes switched over to OTA's, perhaps
on the advice of a young Dave Rossum.

Sean Costello