Flickering amp sound

Discussion in 'Gear & Equipment' started by The Spanish Inquisition, Oct 4, 2017.

  1. The Spanish Inquisition

    The Spanish Inquisition Unexpected

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    Hey guys, I've got a Koch PowerTone and it is a seriously cool amp, but every time I switch it on, right after taking it off of stand by, the sound starts flickering for a while. No distortion, no alteration of the sound, just the volume of the amp flickering between full and completely off. Does any of you guys know why this might be?
     
  2. TedEH

    TedEH Cromulent

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    Sounds like you'll want to do all the normal tube-amp-diagnosis stuff - swap the tubes one-by-one, clean the fx loop jacks, etc. If it sounds normal but just quieter, I'd guess the problem is in the power section. You could try running the pre into another amp (or plugging directly into the fx return on this amp) to narrow things down.
     
  3. TheWarAgainstTime

    TheWarAgainstTime "TWAT" for short

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    Make sure all of the tubes are seated properly and that none of the power tubes are glowing different colors than normal. From there, you can swap in new tubes to see if that solves anything
     
  4. The Spanish Inquisition

    The Spanish Inquisition Unexpected

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    Thanks for the replies. I've tracked the problem to the power tubes. While the tubes are glowing and warming up in the stand by mode, there is no extra light. But once the stand by switch is turned off, LEDs (or what I believe are LEDs) inside of the tubes are flickering. Their lights flicker in the same rhythm as the sound. After a while when the tubes are warmed up, this problem just stops and it functions like any other normal amp. What do you guys suggest? Replacing them? Leaving them be and save myself the money?
     
  5. TedEH

    TedEH Cromulent

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    Power tubes aren't supposed to have LEDs in them. If the tubes aren't functioning correctly, replacing them sounds like the right thing to do.
     

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