2. tech-talk
  3. 1144001143

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
whart's avatar
whart OP
3,037 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
tubes108
153 posts
 
Just a point of reference regarding the Audiopax monoblocks and the Art Audio PX 25 amplifier. I've had both in my system driving Duos. Both are fantastic products. Although the 'Pax are quiet, the Art Audio PX 25 amp has a significantly lower noise floor. The Art Audio could be the quietest tube amp around.

Some people talk about a desire to achieve a noise-free "mystical" blackness where music appears against a noise-free background. Using the PX-25 with my Basis Debut 'table (w/its hydraulic suspension that keeps the 'table immune to outside vibration/noise) this blackness was achieved which adds significant enjoyment. Hearing low level details that would otherwise be missed, and to hear every note played during fade outs is a thing of beauty.

For high efficiency speakers such as Avantgardes, be sure to get the low voltage input option on the Art Audio PX 25.
douglas_schroeder
3,281 posts
 
"...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...

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."

My friend, listen to yourself. You're analyzing it to death.
You have the same problem as me, you are listening to the machinery and not the music.

I have found a simple solution; reading while listening. It distracts my analytical nature enough to allow my asethetic nature to enjoy the music without criticism. Try it.
More to discover