I am new to this forum but it seems that there is a wealth of tallent here. Perhaps one of you could enlighten me as to whats up with this *&)(()^^ amp.
I bought a 2004 Marshall TSL 122 Combo four months ago. It started popping (loudly) three months ago. Replaced tubes. Popping continued. Checked bias. L35 & R48. Replaced tubes again checked bias when left idiling (off standby) time 0 and 1 hour fairly constant. Checked again after playing 2 hours 90 - 120. Tubes cooked again and popping. (Tried fans etc) Brought to tec. Replaced bias pots (not board). Replaced caps, and checked filter caps. Still popped. He basically turned me loose.
Frustrated I disassembled the boards and reseated the connections and changed the contacts on the standby switch to the unused terminals. THe amp worked fair ( no popping but Hum) for 4 hours. Replaced the pre amp tubes the next night and as soon as I powered up the amp popped again. Took out the preamp tube next to the first power tube and put back in the old one. The amp performed again for 3 hours and reverted to popping.
Does anyone know what might be the issue.........is there anyone that can help? At wits end...band and wifey is not HAPPY and 2000$ down the tube is not possible right now. Unemployed ya know!
Thanks for any help that I can pass along to the tech
Fishman
I bought a 2004 Marshall TSL 122 Combo four months ago. It started popping (loudly) three months ago. Replaced tubes. Popping continued. Checked bias. L35 & R48. Replaced tubes again checked bias when left idiling (off standby) time 0 and 1 hour fairly constant. Checked again after playing 2 hours 90 - 120. Tubes cooked again and popping. (Tried fans etc) Brought to tec. Replaced bias pots (not board). Replaced caps, and checked filter caps. Still popped. He basically turned me loose.
Frustrated I disassembled the boards and reseated the connections and changed the contacts on the standby switch to the unused terminals. THe amp worked fair ( no popping but Hum) for 4 hours. Replaced the pre amp tubes the next night and as soon as I powered up the amp popped again. Took out the preamp tube next to the first power tube and put back in the old one. The amp performed again for 3 hours and reverted to popping.
Does anyone know what might be the issue.........is there anyone that can help? At wits end...band and wifey is not HAPPY and 2000$ down the tube is not possible right now. Unemployed ya know!
Thanks for any help that I can pass along to the tech
Fishman
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