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Electrical buzzing sound, or else I'm imagining it

For about a year now I've either had an intermittent problem or an intermittent psychosis, and it's turning out to be really difficult to tell which one it is:

The sound from my system is often dry, reedy, really unpleasant -- even my girlfriend can hear it -- and the problem seems to be of an electrical nature. There's a sort of a buzzing noise through the upper midrange and low treble -- sort of the audio equivalent of those little trickles we used to see on the television when dad was running the electric carving knife in the next room.

If I experiment with different connections (interconnects, power cables, etc.) I can sometimes -- but not always -- make the sound come booming in, perfect, so there's no possibility at this point that what I'm hearing is speaker damage. The trouble is that the bad sound doesn't always go away when I do this little disconnection routine (I've tried every configuration, scientifically), and it always comes back, no matter what I've swapped.

One other symptom that might be interesting: when I get really lazy in my detective work and start connecting speakers to an already powered-up amp and preamp, I can hear a whisper of cloudy-sounding static, almost like the sound your ear would make if it was full of water. I know a person should never hook speakers to powered-up equipment, but in the past when I've done this incredibly stupid thing I haven't heard any such crackle.

It's not the source because it happens on different sources, and it's not any of the cables because I've switched them all out at least once. It's not RF pollution because I've treated the whole system extensively and, besides, it's in the wrong frequency band.

The mains in my house are NOT grounded, so at this point I'm thinking that it's a buildup of fault energy in the amp or preamp, but why would that affect the sound intermittently, and why only in this very peculiar, difficult-to-pin-down sort of way? Could a "bad cap" be the culprit? Any ideas are appreciated. I don't *think* I'm delusional, because non-audiophile friends can hear the difference, but on the other hand this problem has spanned several configurations of gear.
dog_or_man
jea48
4,423 posts
 
The sound from my system is often dry, reedy, really unpleasant -- even my girlfriend can hear it -- and the problem seems to be of an electrical nature. There's a sort of a buzzing noise through the upper midrange and low treble -- sort of the audio equivalent of those little trickles we used to see on the television when dad was running the electric carving knife in the next room.


The mains in my house are NOT grounded, so at this point I'm thinking that it's a buildup of fault energy in the amp or preamp, but why would that affect the sound intermittently, and why only in this very peculiar, difficult-to-pin-down sort of way?
The mains should be grounded..... Even though you may not have 3 wire grounded receptacles your main electrical service is a earth grounded system. The neutral conductor is, (should be), bonded, (connected), to earth ground.

As for an intermittent buzzing sound heard through your speakers of your audio system a loose or corroded electrical connection could be your problem. The loose connection could be anywhere in your home's electrical system. All that is needed for the loose connection to act up is to have current flowing through it. Two things happen. EMI noise as well as generated RFI noise.

It may be time to call an electrical contractor and have things checked out. A loose connection, as a rule, will not cause a circuit breaker or fuse to open. If the load on a circuit is such and the arcing from the loose connection is enough, heat is generated. Enough heat, the connection may burn itself free, or may even cause a fire.

One thing you could try is to turn off every electrical item in your home except your audio system. Listen for a difference. If your system sounds better then it may be time to call the electrician.

I should note if your problem is due to a loose or corroded electrical connection the bad connection could be in the branch circuit your audio equipment is plugged into. It could very possibly be the receptacle. Poor contact pressure between the plug and receptacle can cause EMI/RFI noise. Does the plug feel snug when plugging it into the receptacle?

Also the branch circuit could be feeding many receptacles. If the branch circuit was daisy chained from receptacle to receptacle this could be the problem. A loose or corroded connection/s at a receptacle/s will cause EMI/RFI noise. Receptacle stab in terminations are the worst. Even side terminal screws can become loose or corroded over time.

A dedicated branch circuit could solve your problem.
twoleftears's avatar
twoleftears
5,318 posts
 
I second everything Jea48 has to say.

I would put not just switching off but *unplugging* everything close to the top of your list (off sometimes isn't really off). The next time it happens, have someone stay near the system listening, while you work round the house unplugging everything (everything--even the fridge). If the buzz suddenly goes away, they can shout out and you can figure out what was injecting nasties into the electrical.

Another thought. There are inexpensive electrical testers (looks like a 3-prong plug with several lights on it) that you can go round plugging into all your outlets. The lights light up in a certain way if all is well, and light up in other ways to indicate a variety of faults.

Good luck.
dog_or_man OP
68 posts
 
UPDATE:

Last night I went to a friend's house with all of my stuff. The friend's house is relatively new construction in a quiet suburb, far from urban multipaths and overhead wires, and his listening room is carpeted and plushly furnished and big. We dutifully plugged everything in, powered up, dropped in the first disc and....

....and it sounded exactly the same. Terrible.

This experience would seem to suggest that my problem isn't RF pollution or lousy AC main power, or for that matter room acoustics. We experimented a while, at some indeterminate point trying some of his Acoustic Research interconnects, at which point the kind of musuc that the system should be making all the time came roaring in without a hint of buzz or rattle -- as if I'd just bought replacements for everything and put it all together right next to my own rig.

I suppose it's possible that the whole thing will be fixed from this day forward, simply because his cables are more forgiving than mine. Much more likely, it seems to me, is that the problem has something to do with the act of making and breaking the connections. Either there's some sort of fault energy building up in my rig and it's somehow being dissipated by the act of breaking and reestablishing the connections, or there's a cracked connection inside one of the pieces of equipment, or there's some trouble with the terminations on some of my cabling (which is all essentially brand-new, so I want to think this last possibility isn't it).

Any further thoughts, based on this experiment, would be greatly appreciated. My friend bought me two pair of these AR interconnects, on the spot, but I'd be lying if I said that I thought the magic bullet had been uncovered for a total outlay of twenty-four bucks.
twoleftears's avatar
twoleftears
5,318 posts
 
Sounds like you need to go through your system, one component/interconnect at a time, swapping one piece out and substituting something else and noting the results. Laborious and time-consuming but might get you closer to the cause of the problem. Process of elimination. It does sound as if there might be a loose or partially shorting connection somewhere, either in an interconnect termination or at/behind one of the jacks on one of the components.
dog_or_man OP
68 posts
 
Getting closer!

I just tried this exact sequence, and it worked:

1) I stopped the CD player but did not power off

2) I shut the preamp and power amp off (preamp into "standby")

3) I disconnected the speaker cables at the speakers

4) I disconnected the CD-player from A/C power, and re-established

5) I disconnected CD-player ic's at the CD-player end, and re-established

6) I powered on the preamp and the power amp (with no speaker connections)

7) I reconnected the speakers

I Pushed "play"... and everything was PERFECT.

....So what does everyone think, now?
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