From funkyhammond@yahoo.com Wed Dec 20 12:02:11 2006
Subject:Re: Roland EV-7 pedal

An expression jack requires a stereo TRS (tip-ring-sleeve) plug. A
generic volume pedal wouldn't work unless it also has an expression
output. But any expression pedal may also not work if it's of the
wrong polarity. For example, the Nord Electro is compatible with the
EV7 but many of us Electro users prefer the Yamaha FC7 because of its
longer throw. Unfortunately, the Yamaha pedal is the wrong polarity.
So what some of us do is buy a 1/4" stereo (TRS) extension cable and
resolder one end to reverse the ring and tip (ie. the non-ground
wires). The pedal can then be plugged into the extension cable to
reverse its polarity. I've made two such extension cables -- one as a
backup -- in case one flakes out on me during a show because of my
not-so-perfect soldering job.

If you have an expression pedal, just try it out and see if it works.
If it's the wrong polarity, you'll get strange abrupt volume changes.

> that would shed light on this?
>
> Thanks,
>
> Rich
>