[sdiy] passive pan pedal noise

[peter edwards]

I'm working on a pan pedal for my synth and I've encountered a  
strange noise issue that has me stumped.
What I want to do is send my synth out to two different guitar amps.  
I'm using a reconfigured passive, stereo, volume pedal to fade  
between the the two amps.
The synth signal goes in one jack, then splits to the two sets of  
lugs on the stereo 100k pot. The two sets are wired as normal passive  
volume controls in opposite configurations so when one is turned up,  
the other turns down. The problem is when I plug the two outputs to  
two different amps I get line noise. When I use one, it works fine,  
when I plug in the second amp I get  line noise. It's not extremely  
loud, but it's noticeable/too loud.
I've tried different amps and switched the configurations, but I'm  
still getting the same effect.
any thoughts??
Thanks!
-pete