The Tonepad volume pedal with 3080.

[sean k]

So I've marked this one out on copper and I'm now wondering how to go about setting up the actual pot. Would it be a log pot or maybe even a reverse log?

The question being that do the CA3080's pull down the output when pin 5 recieves a higher current or does it pull down on a lower current.
http://www.tonepad.com/getFile.asp?id=2

I'm hoping that the 100k pot is a regular audio taper and 9V goes in where it normally goes in and the diode to earth is where it normally just goes straight to earth. Are my hopes fulfilled?

[R.G.]

It might help to read Anderton's actual article. His article used the original pot in a volume pedal, whatever that was. I can't remember beyond that. Some volume pedals used audio, some used linear. Don't know of any reverse logs, but it could have happened.

The 3080 multiplies the current into pin 5 by the difference between pins 2 and 3. So the bigger the current into pin 5, the bigger the current into/out of pin 6 is. This is of course a current output, so the voltage output is the product of the output current times the load resistor on pin 6.

More pin 5 current equals bigger signal.

[sean k]

Question answered, thanks!