Hey all,
I have Ampeg SuperJet. The problem is there is a humming and during the first about 20 mins of play there is a buzzing and popping sound (built in fuzz? haha). It fades away after a while. I replaced the 2 EL34's with JJs and rebiased the amp. The two preamp 12ax7's have been switched around and around. It had chinese 12ax7's in there and I replaced them with NOS rca and sylvanias. Both did not fix the problem. Do you think it is worth getting new JJ 12ax7's?

If anyone has any experience with this amp it is very finicky and fussy. It is the reissue version SS-12R maybe 15 years old. The hardware they like to use in these tends to resonate at different note, seriously if I tighten or loosen the backplate screws I can get a buzzing (different buzzing then the tube buzzing).

Any help would be appreciated!