Problem with dirt pedals in my Electra-Dyne

[gag halfrunt]

I'm trying distortion pedals in the clean channel of my ED, and when I get to the high gain sections, it sounds terrible. It sounds like the speaker is farting. I'm not cranking up the volume on these pedals, so I'm a little confused as to why I'm getting this result. I get similar results with low gain pedals into the low gain and high gain channels on the ED.

The low and high gain settings on the amp (without pedals) sound just fine. Also, I've run these pedals into other amps, and they sound fine.

My first thought is that it is a tube problem. But I was wondering if anyone else has had the same problem. I got this amp used, so I don't know how many hours the tubes have on them. And of course, tubes can go bad at any time.

 

[elvis]

I've been turning this one over, and I'm stumped. The pedal should have no weirdness that is not there without the pedal. Time to look at the rest of the system. Bad cable? Ground loop? Weird interaction between guitar and pedal?

If you can turn the gain and volume way up without the pedal, do you get a the farting sound?

 

[SonVolt]

I'm confused. Do you mean you're using distortion pedals on your high gain channel on your amp? If so then it will sound like crap. Or are you referring specifically to the clean channel on your amp and the high gain on the pedal?