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help my amp is messed up


mxpxismyrx

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i just bought new tubes for my cobra, E34Ls. it had EL34s in it so i figured the bias would be pretty close to the new ones. well i stuck em in and my multimeter said 141ma and they got ho real fast so i turned the amp off, now no matter what i do i cant seem to get a right reading on em and it keeps makin loud scratchy noises. on one tube it reads like 9 ma and on another it reads like 45 and then continues to climb!!! it just keeps geting higher one by one. i made sure every contact was good and clean in the sockets already and that didnt do anything, also when i touch the test points with my multitester, it actually makes the amp do more scratchy noises sometimes. on my multitester it has 3 plugs, one says 10ADC, another says V(ohm sign)mA, and the third says COM which ones do i use? aso i have the thing dialed at 200Ma DCV am i doin this right?? any help is greatly appreciated, i really really dont want my amp to be broken, and a weird thing is the amp was fine before i put these tubes in. buut it did have a lil bit of scratchy noise but it was suuuuper quiet. other than that i dont know whats up

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Originally posted by mxpxismyrx

i just bought new tubes for my cobra, E34Ls. it had EL34s in it so i figured the bias would be pretty close to the new ones. well i stuck em in and my multimeter said 141ma and they got ho real fast so i turned the amp off, now no matter what i do i cant seem to get a right reading on em and it keeps makin loud scratchy noises. on one tube it reads like 9 ma and on another it reads like 45 and then continues to climb!!! it just keeps geting higher one by one. i made sure every contact was good and clean in the sockets already and that didnt do anything, also when i touch the test points with my multitester, it actually makes the amp do more scratchy noises sometimes. on my multitester it has 3 plugs, one says 10ADC, another says V(ohm sign)mA, and the third says COM which ones do i use? aso i have the thing dialed at 200Ma DCV am i doin this right?? any help is greatly appreciated, i really really dont want my amp to be broken, and a weird thing is the amp was fine before i put these tubes in. buut it did have a lil bit of scratchy noise but it was suuuuper quiet. other than that i dont know whats up

 

 

 

I'd say stop before you kill yourself and wait for olaf to come aorund

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yeah seriously, im done messing with it, and i tell you what people, get your damn tube sockets replaced with better ones. for a $2k amp. its got cheaper sockets than a peavey. but yeah its just so discouraging. i keep wanting to go mess with it hoping i can fix it somehow. someone pleeeeease shed some light on this!!! i even called the guy from eurotubes and he just kept telling me its dirty sockets. that should definitley not make my tubes blow up the thing is brand new, this is the first time ive ever changed the tubes. and anyways i cleaned em and its still being dumb. grrrr. im so sad i was all anxious to hear my new tone and everything

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well the thing is the tubes are still fine, like i can play through them but it randomly makes loud scratchy sounds, and im 100% sure i have it biased totally wrong. and its my understanding i gotta have it fully on to measure the bias, but the thing gets all weird before i have a chance to, like, it progressivley gets higher in the voltage or something. im not a techie dude so im not sure whats actually goin on

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