[dogorman]

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.

[Ethan Winer]

The simplest solution is to play a 300 Hz sine wave through your system when you think it's acting up. Sine waves have no harmonics or buzziness. So if you hear a pure tone that means the system is working, and if you hear a raspy buzz you'll know something really is wrong and it's not your imagination. This is much better that using full-range music as a test signal to identify low-level artifacts.

It's not difficult to make a CD with a sine wave test tone, but let me know if you need help with that.

--Ethan

[dogorman]

Okay. I need help with that. 

My PC has a DVD burner but not a CD-burner, per se; will it burn CD's? If not, can I make the test tone using a DVD blank and then play it through my DVD player?

Also, I have both test-cd1 and test-cd2 by stereophile, as well as the test cd that came with my hsu research sub, do any of those help at all?

Thanks, Ethan!

Dave.

[ted_b]

I have a 290-300 hz mp3 file that Ethan has on his website.  I'll email it to you (180k, not big, PM with your email) or download the full zip file of all the tracks from his site.
http://www.realtraps.com/test-cd.htm

[dogorman]

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.

[Ethan Winer]

My PC has a DVD burner but not a CD-burner, per se; will it burn CD's?

Yes, DVD burners can also burn CDs using CD blanks.

It is common for RCA connections to get fuzzy over time, and be "repaired" by unplugging and reseating the wires. However, it's very unlikely the same problem will occur equally in both channels. So if the poor sound is equal left and right, I suspect a faulty power supply in one of the components. If you hear it on all sources, then it's something common to all sources like a receiver, preamp, or power amp.

--Ethan

[dogorman]

I have the feeling that we're either zero'ing in on this, or getting to the point where it doesn't actually make internally consistent sense, one or the other:

The act of breaking and re-establishing the connections sometimes makes everything work perfectly, but when the problem recurs it's definitely an electrical sound and it's definitely in both channels.

My un-informed gut tells me that power supply problems shouldn't abate with re-connecting interconnects, and that you're right that a connection problem is unlikely to be equally problematic in both channels -- certainly not with the same exact symptom.

...Does that leave some prime candidate? Is it possible for some kind of (wrong word for it) "static" to build up at the interconnect sockets, as a result of the un-grounded power? In that case, breaking and reestablishing the connections could be (wrong word for it) "discharging" the problem, making things seem perfect for a while.

[dogorman]

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) power on the preamp and the power amp (with no speaker connections)
7) reconnect the speakers
push "play"... and everything was PERFECT.

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

[Mag]

I don't want to appear as a complete idiot so I'm hesitate to offer a suggestion.
The sound you describe as electrical I may have heard before which I describe as a ripping sound. This was caused by too strong a wave signal from my computer soundcard.
One time I was trying to level match my computer soundcard with dvd player to determine if soundcard was as bad as I perceived. What I found was that the dvd wave and volume levels are set at high levels approaching strengths that I knew previously cause line distortion. It turns out that the soundcard was just as good as dvd player with matched levels.
Since you've tried different sources perhaps the extra boost in wave strength is coming from your pre-amp. I suggest trying a different pre-amp.

Just my .02 cents.

[richidoo]

You have dirty connectors. Caig makes some nice products for cleaning and protecting them. It's regular maintenance that is seldom discussed.
Good luck
Rich

[Wayner]

Craig Deoxit-5.

[dogorman]

I just got back from their website, and boy are my eyeballs tired. There's Deoxit D5, Gold G5, Shield S5, and they all seem to do slightly different things: do I use the D5 to clean the contacts and then the G5 afterward (once the D5 dries), to reduce future problems? And each of these products comes in about a half-dozen different forms / suspensions. Eeep.

[Ethan Winer]

power supply problems shouldn't abate with re-connecting interconnects ... I just tried this exact sequence, and it worked

If the intermittent connection is inside one of the devices, merely jostling it will make it work and not work. So doing anything at all might make the problem come and go.

--Ethan