There's quite a few factors at play here, so I'll do my best to communicate the problem succinctly.
I'm having a bad noise issue when using the HX stomp with both:
a) high gain dirt from other pedals in line before the stomp
b) High gain modeled pedals/amps within the stomp
In both scenarios, I'm getting a really bad squealing/whistling feedback sound at a constant level, regardless of how close I am to the amp/pedalboard.
I first noticed this using the Stomp with my musicomlab loop switcher in 4CM into a Fryette PS2. As the switcher has an isolated input and output, I routed the send from the stomp through this into the front of the amp. The FX Loop send from the PS2 goes into the L return of the Stomp, and the L output goes into a Lex and UAFX Golden, finally into the return of the PS2 FX Loop. This routing helped with a much quieter squeal that I was getting initially. However, when pushing the gain to a certain level with a TS9 or other boosts, the louder squealing begins, even with the Stomp bypassed. When I remove the Stomp from the chain, the squeal is gone, regardless how far I boost.
This also happens when I plug straight into the stomp, which I then connect to my computer with the USB output. If I push the modeled amp volume far enough, and use any modeled overdrive/distortion, I get the same squeal. This is just guitar into stomp into computer, no loop switcher or Fryette PS2.
So I guess my question is; is is this typical behaviour for the Stomp? Initially I thought this would be some issue with ground loops and the PS2, but the fact that this can happen entirely within the stomp on its own it tripping me up. I've tried messing with input levels for everything but no luck so far. Does anyone have a similar experience/solution?
Would be much appreciated if anyone can lend some insight
