Using Only One Side of a Power Amp

[bilbal]

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

[Blue Strat]

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

[lastwinj]

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


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.

[mike80]

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?

[Blue Strat]

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.

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.