Preamp Noise with High-Efficiency Speakers

I transitioned from electrostats to the Avantgarde Duos almost seven years
ago. Quieting the system was a major effort, but yielded enormous
rewards. I agree with the above remarks about trying to find the source of
the hum. At a certain point, mine was not pronounced, but I wanted the
system to be dead quiet and worked further on the following things, some
of which you have done:
1. dedicated AC and subpanel
2. running a noisy compressor for my tonearm into an isolation transformer
3. identifying noise inducing appliances that contribute to low level hum on
the system- even dedicated lines don't really 'isolate' the system power
from the rest of the household electrical system. For example, a hi-
intensity, low voltage spotlight over a kitchen sink 3 floors away will induce
hum. Solution- when I am listening, we don't turn on that light. Ditto on a
room humidifier in one of the bedrooms. Finding the source may thus not
even be 'in the system' in my experience.
4. Cable and equipment layout, as others have mentioned.
5. Playing with grounding solutions- for a while, I used that Granite Audio
Ground Zero- a sort of external star grounding system that allowed you to
change impedence on various grounds (these are not a substitute for the
ground to power receptacle but in addition to it). It worked for some system
set-ups, but I'm now at a point in my evolution where I don't need it.
6. Others with more technical experience can weigh in here, but as I
understand it, different components may have different internal grounding
set-ups. That may contribute to the problem.
7. Alot of this is simply time consuming and mind-numbing, frustrating
experimentation and fiddling.
8. Positive note: it can be done! My system is extremely quiet. And the
results are worth it, not just for avoidance of hum, but to yield more
information coming through the system.
9. Anecodotal observation: The Avantgarde Duo is tricky in the extreme to
really nail. A lot of folks critical of it have heard it set up badly. I'm not
suggesting that it is the 'best' or 'better than' anything, but I can get an
extraordinary amount of music out of my system.

Ying: Just keep in mind that the Granite Audio thing is not really a total solution, but in some ways a 'band-aid'- and i had mixed results with it; on some system configurations with different amp and preamp it seemed to work better than others. Just sayin'. And, you really need two people to work it successfully- one to throw the various switches (exponential combinations, when you add in what gear you join on the same 'path') and one to listen to results. You also may have to order more of their grounding cables and longer lengths to get it to connect to various components. (and yet another variable is not connecting to some components). I bought mine back in 2007 or so, it is far cheaper than some of the esoteric external grounding solutions available today, but imagine if you are handy, you could come up with a DIY solution. ( Ralph or Almarg might chime in here), you may be fighting potential grounding problems within the components themselves. None of this is easy, but it's more labor than anything to get it sorted.
Let us know what you come up with. I hate hum!

Neat post, German B. And that guide book is pretty clearly written. Nice contribution!

The original purpose of the thread was to discuss noise abatement using a very high efficiency speaker (one which I own). George, I have great respect for what you do, but I think the proselytizing is a bit much since many of us have a variety of experiences using different sorts of set-ups, passive and active. I'm not sure this is the place to debate the merits of passive preamps.
And I say this without being condescending. I just recognize that there are many ways to get to the end result, which is music.
No disrespect intended, either to you or to Mr. Pass.

To his credit although Atmasphere (Ralph) is a manufacturer, with a vested interest in his own gear, I find his responses to be intelligent and open-minded.
George is basically insisting that his way is the only way- and that is just wrong.
FWIW, I experimented with bypassing the line stage and running directly from a phono pre into the amps (It was a Steelhead, which has more circuitry than a stand-alone passive pre, but the overall concept is similar and I've since replaced it with something a little more antiquarian, using LCR and transformers, along with old telephony tubes, which to my ear sounds better). Although the bandwidth was great, bass to die for, the presentation sounded threadbare and very 'hi-fi.' Introducing a good line stage into the mix added a level of heft and palpability that I associate with real instruments. Changing line stages last year upped the ante even more -going from the Lamm L2 to the Veloce (Lithio or version 2). Piano is a hard instrument to reproduce. For years, we had a big Bosendorfer downstairs. I know what a real piano sounds like. It's a beoytch to reproduce, and beyond the gear is the quality of the recording, how the instrument is miked, how the record is mastered, etc.
So much is source and system dependent, and so many other variables make up a system, I just can't buy into 'my way or the highway' approach to hi-fi.
Sorry George, you've lost me on this thread.

Charles- I'm open to learning, considering other approaches and contributing where I can. I can also enjoy a good debate, but after too many years on the intraweb, don't have any interest in sniping, at George or anybody else. I enjoy (and enjoy sharing) the excitement of discovery, the fundamentals of 'best practices' in set-up, the detective work of trouble shooting (not easy in void of hyperspace) and fiddling with tweaks that don't cost a fortune. I also enjoy hearing from others who consider this an adventure. There are many here that seem to approach things the same way- they don't discount novel or antiquarian approaches ( although there may be some legitimate skepticism); but, at bottom, folks here are often willing to jump in and spend real time, thought and energy to help somebody troubleshoot a problem or answer a question. (I've certainly benefitted from that over the years here).
As somebody put it in relation to a discussion about the sonic differences among various pressings of the same record, it is still more art than science in a lot of ways, even though sound engineering principles should underlie what we do.
I'm not dumping on George, but find the endless drum beat to be monotonous, and ultimately, counterproductive, at least for me.