If it's loud enough to hear over moderate volume music, I'm guessing it's not the typical transformer "buzz". The periodic nature of it concerns me. Of course, trying the typical fixes for that problem described by others can't hurt. Not sure I'd go so far as resoldering all of the joints until you figure out if there is a bigger problem.
Buzz coming from power amp - not through speakers
Hi, first post here. I just picked up a Harmon Kardon PA5800 off ebay. It sounds great, no issues there. However, the amp itself makes an intermittent hum/buzzing noise (ie, the sound comes out of the amp unit, not through the speakers). It fades in, peaks, then fades back out with a period of about 5-7 seconds. Sometimes it's not noticeable at all, but occasionally it's loud enough to hear even with a moderate volume level through the speakers.
Anyone have ideas? DC noise on the AC line? Basic service needed, ie new filter caps? (I'm a tube guitar amp guy, not even sure this type of amp has filter caps).
Anyone have ideas? DC noise on the AC line? Basic service needed, ie new filter caps? (I'm a tube guitar amp guy, not even sure this type of amp has filter caps).