Ok. So I have an MT15 and if I turn the volume to 8 o'clock or higher it has a really loud squeal while I'm pressing down on the strings. It does it on my fishman modern loaded guitar, an EMG loaded guitar, Nazgul loaded guitar . I have a Gibson V with a burstbucker 3 and it's not too bad and I have a JB loaded guitar that I potted myself that doesn't have a lot of noise. Today I bought a Mogami Gold cable and went straight into the amp. Still does it . I had put all tung-sol 12AX7's in the pre and a 12AT7 in the phase inverter. Pulled em all put the JJ's back in same ****. I have EHX EL34's in the power section but haven't messed with those yet . Any ideas?