Okay, so i have this Bugera 333 tube amp. It is 120w all tube and i got it by a craigslist trade. The amp worked fine for several months, had just been retubed by the previous owner. All good tubes blah blahh...now this thing was loud, like on stage at an outdoor festival venue it would be too loud at idk 3 (out of ten) then at rehearsal one day i set my amp up, go to play and boom not even one half the volume i used to have. I had this thing cranked at 10 maximum and it would not overpower my speaking voice. I changed guitars, went direct from guitar into the amp as opposed to my board, tried a different instrument cable, tried a different speaker cable, nothing. The clean channel was very quiet, the overdrive was a little louder and the lead a little louder than that. Yet still like a 50% volume drop at least. I bring it to my uncles the next morning so he could see whats wrong, and it worked perfectly...He checked the tubes and everything, wicked loud and good, just like new. we fgured electrical problems at my rehearsal space, i go home....stopped working again! i bring it to a amp repairmen, he keeps it at his house for a couple days, test runs it through and through and it works fine for him. no issues. i havent gotten it back yet but what if it wont work for me??? what is causing this? Also, its not the cabinet because as we speak i am using my uncles Egnater renegade 65w head as a backup annd it works fine.