amp transformer hum through speakers ?

I'm not sure what causes it--all amplifiers hum (some more than others, of course)--and I think it's inevitable that you hear that through the speakers, especially though more sensitive speakers. I have 96dB effcient speakers with 1,000W built-in subwoofers, and I can hear the hum from the subs' tranformers if I get close enough. Fortunately, I generally can't hear it from my seat.

Could be a ground loop hum. Or it could be the amp is too close to the speaker.

Mine has always been caused by a ground loop hum, and fixed with a 3-into-2 cheater adaptor. Either that, or mine have hummed when the tubes are not evenly biased.

Hi Mike,
if this is giving you problems, try a set of HT cberlinks between pre & power/s.Cured all sorts of problems I was having, probably due to breaking the grounds between the components. Mail me direct if you want to discuss more.
Simon

you have to distinguish between transformer hummmmm and ground loop hummm. Ground loop usually can be delt with either a cheater, 2 prong pc (Vans Evers comes to mind, they have a grounding wire so it can go either way) or a ground isolation transformer for your cable TV line (vbery common source). Transformer hummm is a physical thing actually harder to deal with. Sometimes it results from excessive dc leakage and there are products to handle that (one by auidoprism I think). Sometimes its poor design or construction of the transformer and then there may be no hope.