Buggy standby - Fuchs mod...

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by Riscchip, Jun 4, 2006.


  1. Riscchip

    Riscchip Member

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    Does anyone have an idea what might be causing the standby mode on my Fuchs modded bandmaster to fail? Switching the amp to standby, volume is greatly reduced and output is sputtery, but I can still hear myself playing. Wondering if this is anything simple that I can fix myself, or if it's time to take it somewhere.

    Thanks for any help!
     
  2. jspax7

    jspax7 Member

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    The standby on my production ODS 30 is not immediate. It slowly decays. I think it's by design.
     
  3. Riscchip

    Riscchip Member

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    Thanks for your thoughts on that, mate. Much appreicated. I also remember the slow decay function from my Fuchs DRRI mod that I had a while ago. Thing is...even after several minutes, you can still hear output from this amp in standby mode--it doesn't cut out completely. Perhaps is some function of whatever makes the cutoff decay that is failing? Or maybe it is by design that it behaves like this, hmmm.

    Thanks again.
     
  4. donnyjaguar

    donnyjaguar Member

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    Here's a guess. There is a resistor across the swtich which bleeds a little bit of voltage into the amplifier even when it is in standby. I did this to one of my old hi-fi amplifiers for the purpose of getting around what they call sleeping sickness in tubes. Basically tubes that are idled with no current for long times lose some of their gain and go weak. I put a 1M5 resistor across mine and yes you could still hear it amplifying, albeit weak and distorted.
     
  5. Riscchip

    Riscchip Member

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    Welps, I heard back from Andy Fuchs, and he confirms this is a non-issue. Has to do with the very large filter caps in this amp.

    I guess I can't find a darn thing wrong with this bad-boy! :)
     

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