I took my older crate tube amp to Shane at Aum Amplification because of a loud hum that seemed to get worse on the dirty channel and/or if the gain was cranked up. I told him of the things I had tried to correct the situation so far. He said he’d take a look at it and get back to me the next day. When I heard back from Shane in less than 24 hours, he’d tested all of the components and added some grid resistors to help with interference. He then had me plug my gear in in order to determine what was being caused by the amp and what was the petals, pickups etc. He also was honest enough to explain what he could and could not eliminate in regards to the hum and talked me through the set up of the circuit board. By the time he was done, I could still hear the natural 60hz hum found in these types of amps(and my tele has single coil pickups) but the loud buzz was gone, even on the dirty channel, or with the OD petal plugged in. I would definitely recommend him for any amp repair you might need.