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High Efficiency System- Noise Floor Reality Check?

Trying to gauge whether I'm expecting too much quiet with the system at steady state, ie idling, no music playing. System consists of Avantgarde Duos, with the latest version of the Audiopax 88 monos; Steelhead preamp running a single phonoplayer (The TT, arm, cartridge and wire to the preamp will change in about a week).
Everything is plugged into a pair of Shunyata Hydras- two separate units, one for the speaker/amp woofers (Hydra two, with two outlets; the other a Hydra 6, into which the Steelhead and Audiopax amps are plugged). Using fairly high grade Shunyata power cables on everything; the Hydras, in turn, are plugged into a Richard Gray Substation, a 240v step down transformer that has its own line.

What am I hearing?- well, if you put your ear up the tweeter or midrange horn, a soft 'zzzz' type electrical noise, and from the woofers, a muted 60 hz hum. From the listening distance you can't hear it at all. And, when you crank the gain up on the preamp, no music playing, these noises don't get any louder.
Am I hearing the invariable low level noise of electrical equipment through very efficient speakers? I'm not so anal as to believe I can eradicate all system noise on a set up of this type, but I'm concerned that even this low level of residual noise may interfere with the system's musical capabilities. Would love to hear from high efficiency types since this is my first horn based system.
I also have a good electrician who has helped me in the past, but I'm not sure there is anything he could do beyond this to improve the noise factor, is there? Reality check? TIA.
128x128whart
cmo
471 posts
 
Porziob........ Not so fast.

Whart,
The 60 cycle hum should not be there. With my Duo's, Aesthetix, Art Audio (i.e. all tube system) all I hear when I put my ear next to the horn is a gentle tube hiss. I am not using any type of power conditioning in my system at all. I have a Shunyata Anaconda VX on my CD player, Cardas PC's on my subs, and an Argento PC on my preamp....... other than that all cords are stock. The thing I have done however is to run four dedicated 20amp lines, off of a dedicated breaker panel with it's own grounding etc.

I have the lines seperated for digital, analog front end, power amp, and subs.

I would try pluging your components into different lines if you can. You might try removing the powerstation, etc..... In short experiment until you get the lowest noise floor. If you can't get it to completely go away try your electrician buddy.

Chris
herman
2,216 posts
 
Chris has different electronics so you can't really compare. I agree with his advice to try various things to minimize the noise, but if you hear nothing at the listening position with these then you are in good shape. What matters is how it sounds at the listening position while playing music, not how it sounds with your ear up next to the speaker.
whart's avatar
whart OP
2,977 posts
 
Well, you guys represent the extremes of the internal debate I have been wrestling with- it shouldn't bother me, but I don't like knowing it's there.
FWIW, I have already tried virtually every permutation I can within this room; I have yet another set of dedicated outlets that take from a leg of the 240 line that feeds the stepdown transformer, but this may still be affected by what's on that line, i guess.
As to the differences in electronics, no doubt you are right, Herman- the Audiopax amps are, as far as tube rush goes, quite quiet. But, there is that hum. Damn!
The only way to know for sure is to have another completely separate subpanel, with 20 amp lines set up and run into the room. So, I'm going to probably talk to my 'guy.'
Oh, and the sound at the listening position does keep improving. At first, I refused to invite the devil into the system by way of a CD player to break things in- so I was doing speaker break-in the long way, through playing and listening.
Then, I got impatient, so I hooked up a little portable and found my copy of Art Zoyd's 'Nosferatu,' a virtually unlistenable little sonice nightmare that is perfect for breaking stuff in. Let that run for a day or so;
still fiddling with speaker position and woofer settings, but the bass on a good recording is impressive and musical, if not real. (Again, went to a club last night down in the lower east side and listened to a couple bands- the kickdrum is impossible to duplicate, at least in my smallish listening area with this somewhat 'modest'system).
Thanks, all. :)
plato
1,543 posts
 
Whart, if you want to get the lowest hum possible from your system there is a simple device made by Granite Audio called the "Ground Zero" that may banish or seriously diminish the hum. I'd almost think it would be a must for a high-efficiency setup like yours. Here's a link to more info: http://www.graniteaudio.com/zero/index.html

The zzzz from the tweeters could be a differnt problem, possibly improperly shielded interconnects...

BTW, that's a great looking system you have there and I'd love to hear it sometime. I was very impressed by the Audiopax electronics when I heard them at T.H.E. Show in Vegas this year.
cmo
471 posts
 
Whart,

Have you tried cheater plugs........ Probably an obvious "Yes", but thought I'd ask.....

Chris
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