Just need help trying to figure out what's wrong with my amp. A couple weeks ago I bought a Vox AC15HW used, tried it at his house, sounds great. I brought it home and tried it with my rig, the next day at church I noticed some buzzing and quite a bit of noise. After about a week playing around with it, I notice some noise in behind my playing (egg frying noise) and volume jumps. It got worse as I added gain. Naturally, the first thing I did was change the tubes. I had a few extra power tubes that I put in the amp, and also added some brand new tung sols in the preamp section, as well as an older sovtek lps for v3, which I had lying around for a while. With the tube change, amps sounds really good. No noticeable volume jumps, but I still hear the background noise behind my playing. Everytime I strike a note, I hear the amp buzz a little bit. It's not really noticeable playing clean, but as I add gain stages with my pedals, it seems to get louder and more obnoxious. Could it be one of the older tubes? Or maybe something else? I don't really know where to start to be honest. Oh, also I tried with and without my pedals in the chain, didn't make a difference in noise.