amp transformer hum through speakers ?

what causes 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.
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.

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 :