Volume drops, farting

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by 85db, Jan 18, 2006.

  1. 85db

    85db Member

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    Hey folks,

    My Marshall 6100 started to crap out on me. After about 5 min of playing the clean channel becomes farty and both dirty and hot channels' volume drops severly. Letting the amp rest for a few hours "cures" the problem and then it starts all over again.

    What could it be?
     
  2. zach5150

    zach5150 Guest

    My .02 cents says most likely cause is worn out power tubes....new tubes and a bias....how old is the amp? What kind of amp? When was the last time tubes were replaced?

    Oops....edit: I see you posted it was a Marshall 6100....
     
  3. bob-i

    bob-i Member

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    Heat related problems are difficult to troubleshoot. If the tubes are not bad, which is always the first thing to check, then there are some bad connections, either solder connections, tube sockets or if they're in the amp, ribbon cables. It's also possible that there are circuit board cracks (I believe that this amp is PCB, not sure).

    Best take it to a tech.
     
  4. 85db

    85db Member

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  5. zach5150

    zach5150 Guest

    Yeah, I read that thread last night, or this morning I think...of course, it was shorter then! Anyway, I wasnt sure what to think. I've got some winged C 34's in my '87 JCM 800 2204. They've been in there for about 2 or 3 years....I dont gig that amp, but I do play it and they have been quiet, strong and full of tone. I really liked 'em, so I bought some others and they sounded good, but had all kinds of mechanical noise. But, then I've had the same deal w/ JJ's....sound excellent, but sometimes, I get that mechanical noise that drives me nuts! That's one of the reason's I'm moving away from combos I think......i love combos, but the tubes just get beat to hell.....The Svet's are in the JCM800 head, and have been trouble free...any tubes i put in my koch combo get noisy...fast.....
     
  6. 85db

    85db Member

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    The link I quoted above no longer valid. The discussion got out of hands and moderators deleted it along with all of the posts about Winged C tubes. There were other people there that had similar problems with the quality of Winged C tubes.

    I got a brand new set of Winged C EL-34 tubes, put it in my Marshall and couldn't be happier. However, while playing the amp today the volume dropped again!! That's weird because I biased the tubes around 68% and played them for 1.5 hours total.

    I'll recieve a set of Mullard New Sensors tomorrow and will play those for a week to make sure it's not my amp.
     

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