Problem with AC and how to solve it

Audiophile APS 1050 regenerator- will output a perfect 120 v/60Hz sinewave when your wall voltage is anywhere from 80-144 volts. It should solve all of your problems if you feel they are related to flucuating line voltage. The 1050 is also a UPS and has short term battery power usage, with additonal battery packs available. It's a very good unit- I used to have one.

http://www.audiophileaps.com/

PS Audio Power Plant P-500 or P-1000 AC regenerator.

It is probably not a voltage problem at all. You are carrying noise on your lines from something. It could be as simple as a light dimmer or something similiar.
Some sources of lighting will cause it. Probably need to turn things off in your home until you find the culprit.
As long as the AC is clean, slight voltage variations don't mean much (other than affecting the maximum output of the amp.) Most power companies operate in a + or - 10% realm. It is not unusual for voltage to drop down to say (maybe even lower) as low as 108v (sag) in the summer and then peak up to as high as 127v or more at other times. If your voltage is outside of these approximate values, you will need to contact your power utility and see what is going on. It will effect your refrigeration and air conditioning systems adversely also. Actually anything with motors. When voltage sags, amps increase and when voltage increases, amps decrease for a given load. Fortunately, most motors have a service factor built in that helps motors survive unusual situations. Over voltage can be as bad as under voltage.
A severe under or over voltage would be required to cause noise in a transformer, if then. I feel confident your amps are suffering from some sort of RFI or other noise on the line. It could be coming from about anywhere.

Totally correct! It is the Current that makes the differance not the voltage. So if its buzzing then there is something else wrong. All that you need to look at the voltage level is a Digital Volt Meter. You can see if its actually a voltage flux or not. My guess is a bad dimmer somewhere or a balast from another product on the same line.

Try a PS Audio Humbuster. Worked for me!!!

Brad Day
Atlanta, GA

Or it could be that there's DC present in the house power wiring at certain times of the day. DC will cause a transformer to buzz. This is a power quality issue; there are power conditioners out there that can address the problem such as PS Audio, Furman, and others.

BigTee had one of the best responses I've read on the site. I remember a halogen standing lamp that had me convinced it was a ground loop and a single misplaced power cord too close to an interconnect.

Consider getting an electrician to test your home's electrical. If there is a problem, I saw a 5KVA 110 volt regulator on Ebay for a ridiculously good price but shipping would be expensive for the 250 lbs. That's almost 50 amps and could handle most of the house.

If the problem is dirty power from within the house and it can't be turned off, another way to go is isolation transformers. Digital gear is prone to causing electrical noise.

I'd recommend Tripplite available at digikey.com or newark.com.
These power conditioners are being used for X-ray machines at hospitals so the power quality speaks easily for itself.

Some sort of regenerator is worth it. Solves all sorts of issues and just makes things sound better. If you can hear the noise 10' away just think about the stuff you can't hear that is effecting sound. Ps audio seems to be the most popular.

Thanks everybody. I'm new on this site and I'm quite amazed by all the help I'm getting from you guys. Not beeing a true audiophile, I've never been truly interested in the technical aspects of the hobby (passion).Though I recognize the importance of a decent rig, I mostly concentrate on music. But when a problem arrises that prevents me from appreciating the music, I'm always glad I can count on someone who understands what is going on inside de boxes.

Following Bigtee's response, I unplugged everything in the house to see if it made any difference. It didn't but I realized that I heard the damned buzz even when the amps are off. I went outside the house and realised there is a similar noise coming from the transformer (witch is about 50 feet from the house). I think the noise is mechanically transmitted to the house by the metal cable to witch the electrical wire is attached. That would mean the transformer is vibrating quite a lot. Of course that's different problem (I think). The question is this: could a buzz (or hum?) in the transformer outside the house generate a similar problem in the transformers in my amps?

Or should I simply have a few more single malts and forget about everything?

Could anyone explain in a few words what RFI is?

P.S. English is not my first language. I hope you will excuse the mistakes I probably made.

Thanks once again.

The mechanical noise of a transformer may not affect the electrical at all unless it is the noise is caused by severe overloading In that case, current can vary. Roughly 50% of transformers hum naturally or because of the poor quality of electricity they are supplied.

If the noise is physically transmitted through the wire, like cans and string, contact the utility and request(demand?) a solution.

You have a request for information about RFI? Radio frequency intererence is generated by most electronics but more so by high frequency devices such as digital and video. It is transmitted through the air as opposed to EMI, which is transmitted through wires.

http://www.arrl.org/tis/info/rfigen.html

Thanks Ngjockey, very usefull info. Following your advice, I called the utility. They kept me waiting for about a half hour. I finally talked to someone to whom I could explain the nature of the problem and guess what, this guy is an audiophile!!! He told me that since I was the only one plugged on this transformer I should not hope for any solution on their part unless the transformer blows. He suggested, like some of you guys did, buying some power conditionning. I think I'll do that.

Halogen pot lights were the cause of buzzing in my system.