amp transformer hum through speakers ?

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.

After re-reading post title it says "coming thru speakers" so it must be a ground loop or other electrical issue. Run a search on ground loops or hum and you will lots of detailed suggestions. If you have cable TV anywhere in that system, look at it first.