Ive searched and found nothing on my situation so here goes...I play through a Gk 1001rb and use a Stingray as my main rig. Attempting to get a suitable Muse tone, I bought a new Bass big Muff. I am satisfied with the tone it produces but here's my issue. I like the switch on the Muff to be up in the bass boost mode, but it does it in the normal mode as well . As soon as I turn on the pedal, even with the guitar turned all the way down, I get massive low-end feedback. I have the sustain dialed about 4 oclock, the tone about 5 oclock and the volume set to match whether is on or off. I can get rid of the feedback 2 different ways, #1 turn down the sustain ( this loses the tone I am looking for), #2 turn down the bass on the amp ( now I lose the tone as well). I'm stumped! any ideas.