amp transformer hum through speakers ?

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.

I know someone who had a Tice power conditioner radiating so much that it induced hum into the woofer voice coil.

But that was a very unusual problem. If the amp transformer radiates that much, then that indicates a problem with it. There is an easy way to tell, if any one cares to know.

Most likely ground loops.

Pat

Hi there,
I should have qualified my reply by saying - if all else fails !
Had lots of problems with grounding loops trying to improve? my house earthing. An extra earth spike connected to the system was great with one amp & caused an obvious and immediate loop with another - I had to revert to the 'house' earth with my Pass.
I found a fabulous link on the threads to a great post on hum tracking - I hope the author does not take umbrage - it was so in depth I posted it on my website - can't remeber where to find the original so with thanks & apologies to the author :
http://damnhifi.mysite.wanadoo-members.co.uk/

Simon