Using Only One Side of a Power Amp

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by bilbal, Mar 11, 2008.

  1. bilbal

    bilbal Member

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    On another forum that I visit the question arose of if it's alright to only use one side of a power amp. I wanted to bring the question here and see what you all think. I don't know why one would only use one side but it happens. I was always told that the amp needed to have a load on it to avoid damage. The guys there were saying that they have used only one side and just kept the "volume on zero" and the "presence wide-open" on the other. Won't this damage the amp? The amp in question is a Mesa Boogie 2:90 Stereo Simul-Class.

    Thanks,
    bilbal
     
  2. Blue Strat

    Blue Strat Member

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    The most foolproof way to do this is to remove the power tubes from the unused channel.
     
  3. lastwinj

    lastwinj Member

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    will cause a rise in voltage in the heaters and b+, dependent on regulation of the power tranny. i would bet the rise would be 5-10%, maybe more.

    personally, i would use a load, but either way will work as supposed to.
     
  4. mike80

    mike80 Member

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    I used only one side of a Mesa 50/50 for over a year, probably 8-10 hours a week with no issues. Just had the volume turned down on the channel not being used...and I'm thinking I got that right from the Mesa manual.

    Aren't most amps equipped with an shunted input jack that keeps the output section idle when there's nothing plugged into the input?
     
  5. Blue Strat

    Blue Strat Member

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    Yes on the B+ but as long as the caps are rated accordingly. It's rare to find good designs where things will blow up with a 10% increase in voltage but who knows?

    If the heater voltage increases the design is seriously flawed.
     

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