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Tube amp problem

Discussion in 'Amps and Cabs [BG]' started by Pete Atkinson, Aug 4, 2000.

  1. Hey guys, I have a tube amp problem. I was playing through my Mesa 400+ last night when I noticed my bass was cutting in and out. I looked to the back of the amp and noticed that the power tubes were glowing bright orange in the MIDDLE of the tube ( I know that this is abnormal ). Before I could shut off the power the fuse blew and that was it.
    I took of the top and bottom covers and did not smell or see anything burnt, I did notice that the one of the transformers was hot and the other was just luke warm. Does this sound like a blown transformer or something else? Please help.


  2. Doug


    Apr 5, 2000
    Buffalo, N.Y.
    Usually if the plates are glowing it's because your'e bias has drifted drastically. You may have a tube going also. Get it checked out, by a good tech., before using it again.
  3. You lost bias or had some tubes go gassy from overheating. What you saw was the plates overheating from too much current flowing. Have it checked out by a good tech. You probably did not hurt the transformers, but you will probably need new tubes.


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