[sdiy] passive pan pedal noise

[Stewart Pye]

Hi Pete,

Guitar guys have this problem all the time. If you do a search on 
diystompboxes.com you'll find threads related to it. There should be a 
schematic on geofex.com.

Basically you need to isolate the ground going to the guitar amps. The 
best way to do it would be to have an op amp buffer driving an isolation 
transformer on the output of each of the pots.

Cheers,
Stew.

peter edwards wrote:
> 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
>
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