Amp volume low, gets loud, crackles
I have a Bugera 333XL 2x12 combo, and I know what you're all thinking, it's an unreliable amp and I knew that before I bought it, but I took a chance anyways. It's been fine for over a year, but recently it's started to have this problem.
So for the most part the volume it puts out seems normal to me, but then every once in a while it will get really loud, maybe twice as loud, and it will make a bad crackling and cutting-out sound.
I've tested with multiple guitars, multiple cables, and without pedals, so I know it is isolated to the amp. I swapped the power tubes with a new set and I'm still experiencing this problem. My next test is to swap the preamp tubes when I order some more, but I wanted to get some input on what the problem might be.