Tweet
Mesa Boogie Triple Rect - This amp has a "bad plate load resistor" sort of hissing and crackling sound. This is mostly on channel 1 though is there less on other channels. The Gain knob of channel 1 when touched makes a bad ground sort of noise but no other knobs do this. When Gain is maxed out the hiss goes away, as it also goes away when the gain is at zero... everything in between maintains the hiss at one consistent volume. I measured 300mv on center lug of the gain pot, not sure if this is abnormal or not. I put new pot in w/ no change. My main question is do these amps just do this due to their inherent hi gain structure or does this sound like a problem? Maybe a bad coupling cap linked to the Gain pot?