Hello All, A friend of mine has a Harmon Kardon integrated amp approx 10 years old don't know the model etc.- the amp emits a constant buzzing sound when powered up , inaudible when cranked right up, but she has just moved to a small unit so low level playing is required most of the time, any thoughts???Sounds like the hum from an old refridgerator!
sounds like a ground loop hum..
you get that when multiple pieces of gear are connected to a common ground through different paths. you alleviate by getting all grounds to a common point.
there are a number of commercial products that help, one being the quite good ebtech(which I use and reccomend)
Thanks NC,though I'm not sure that the problem, as it has only recently appeared (last 18 months or so)-the buzzing sound is coming from the amp, not through the speakers - sound more like a mechanical vibration???
Try to tighten the screw in the transformer inside, but be careful, and remember to unplug it first...
hmm... probably due then to bad isolation of the transformer .
maybe you could try resting it on something dead...bluetak/etc.
Thanks guys, turns out it was the transformer in the CD player,she has them stacked -amp on top of CD- nothing I can do about it- transformer is a small sealed unit, no screws to tighten- but on the way home found an early model marantz CD player w/remote for $20 in a second hand store!
Good news. Determining the cause is 90%.
Sometimes it takes only an inch or so of separation (like putting blocks of wood between the components.
Hopefully the new player solves it.