MOTM

On 4/7/08, Robert Holmström put forth:
>Anyone got a a MOTM-850 pedal interface lying around? Or maybe just a PCB?
>
>Or does anyone know of a similar product out there (could be DIY project)?

A pedal is a pot wired as a voltage divider.  Typically, the wiper of
the pot is connected to the ring of the plug, and the jack is wired
like this:

tip -- voltage in
ring -- constant voltage out
sleeve -- ground

I don't know what the difference is between the Roland and Yamaha
pedals to which the MOTM-850 description refers.

While the 850 does have a number of features, if you had a panel, it
wouldn't be too difficult to build your own using a MUUB or project
board using a few op amps.  It looks like the "Range" function could
be duplicated by controlling the voltage going to the pedal, and the
output from the pedal is summed with the outputs of "Mix" and
"Offset".  The gate feature is likely a comparator that looks at the
pot and pedal output.