Did anyone manage to ``repare'' a buzz, ever?

Is all your gear on one plug or circuit, meaning components on one circuit and amps on a seperate. If so, you may have a ground potential issue.(use an extention cord and test by plugging all devices and amps in same circuit) I am presently experinecing the same thing and found cheater worked on my pre-amp and amps, I basically lifted the ground..

Confused about the x-over issue, see if you can borrow the same preamp or another and test.

Matt

Many thanks to all the participants of this forum. I am trying to use all your help and have some answers and more questions to ask.

Ktsteamer:

It is an interesting possiblity. I indeed have the room's lighting on a dimmer switch in a different room, which is exactly above the listening room. In my experiments, I made sure that it is swithched off, but I wonder if, even so, it may still creat a buzz???

Mzn50: I plug them all into one power surge protector and
line conditioner. I tried the cheater and checked the polarity too. I also connected the chassis of the preamp to other various components. The crossover I mentioned is in the separate power amp for the sub, that is, not in the preamp in question. So, I can run the full range signal from the preout in the preamp, and then can cut it off below 80hz, by engaging the sub amp crossover. This kills the buzz in the subwoofer speaker. Hence, it is not a 60hz ground loop hum?

Thanks.

I'm not an electrician, but I know dimmer switches emit heavy ac waves, even when turned off. So your gear might buzz even with the lights off. If it doesn't buzz hooked up to another socket elsewhere (without a dimmer attached to that fuse), then it's the dimmer switch. Or, if the buzz gets louder when the dimmer switch is set higher, that's a good way to find out too. Also, if the lighting is track, there will be transformers present somewhere - maybe in between the wood beams between floor levels. They also emit ac waves. If you find the dimmer/track lighting is the reason, you can replace the switch will a standard on/off switch, and that might reduce it a bit. If it's the tracking light/transformer, then short of gutting your ceilings and installing new lights, I guess you'll just have to deal with it (I have to). Make sure to throw the fuse switch before installing a new light switch. Hope this helps.

I had a buzz that a technician fixed by re-soldering some connections that had hairline cracks.

On the off-handed chance this may help....a few years ago I found the source of a buzz in my system thru luck. The system was completely ground-floated except for the tube preamp and, at higher volumes with no source signal, it was very clear - annoying bzzzz. After trying quite a few things, I grabbed the metal rack to support myself and moved to the back of the preamp to take another look and touched the case. No, no shock! Just no buzz. It completely disappeared! I wound up taking a lead from the pre's grounding post to a connection on the rack and have been happy ever since....well, except for that tweaking stuff! Good Luck!