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Is a stereo amp, when bridged to mono, by definition differential?

I've been reading about amps and the seemingly endless choices that designers make, and found myself wondering this, but haven't been able to find the answer. It would seem, if I'm correctly understanding the definition of differential, also called push-pull, that bridging the two sides of a stereo amplifier would, by necessity, be creating exactly this topology. Unless I'm missing something, of course, which may well be the case.

Thanks to those who understand such things much better than I for any clarification.

Also, those who'd rush to weigh in about the likely sonic benefits -- or detriments -- of such arrangements needn't bother, as that's not what I'm wondering about.

Thanks.

-- Howard

hodu

Showing 2 responses by atmasphere

atmasphere's avatar
atmasphere
12,104 posts
 
If the balanced input only operates when the amp is bridged, then it is considered balanced but not differential (even if the individual channels are differential). set up this way the Common Mode Rejection Ratio (CMRR) will likely not be very good. Some mbl amplifiers are set up this way.

If the balanced input works in both bridged and stereo mode, then its likely that it is a differential input and performance will be better.
atmasphere's avatar
atmasphere
12,104 posts
 
If you are talking about one of Steve McCormick's designs in the context of this question, you have no worries. He knows what he is doing and his inputs work correctly.
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