Electrostatic speakers and low volume resolution

You are quite welcome.

Should I point out that tubes have a reputation of doing low level detail better than transistors? The more resolution you have (and ESLs have a lot) the easier it is to hear this.

However since you have Martin Logans, in order to get a tube amp to play them right, a set of ZEROs (www.zeroimpedance) is advised. This will allow a tube amp to deal with the near-short impedance that occurs at high frequencies in the Martin Logans.

"However since you have Martin Logans, in order to get a tube amp to play them right, a set of ZEROs (www.zeroimpedance) is advised. This will allow a tube amp to deal with the near-short impedance that occurs at high frequencies in the Martin Logans.
Atmasphere (Threads | Answers | This Thread)"

Don't the output transformers that most tube amps have, do that already?

^^ No. I don't know of an output transformer that is designed to handle a 0.5 ohm load!

Fortunately this impedance occurs at about 20KHz, so there is not a lot of energy involved. But if you are using a 4 ohm tap on the amp to drive the speaker, the feedback needed to cause the amp to give flat frequency response might be insufficient. The ZERO solves that.

Going back to an earlier discussion where I asked advice regarding the use of tubes with electrostatics, I kind of abandoned the idea because a number of issues arose that were a little involved for me to get comfortable with. One of the main ones of these was the prospect of finding a tube amp with a 2 ohm tap and whether using the ZEROS at the 4 or 8 ohm tap would accomplish the same thing. Based primarily on Atmasphere's explanation I assume that both approaches are viable and equal(?) in their ability to handle these extreme loads. I'm not claiming any kind of complete understanding of the relationship of feedback to distortion or its control, but my gut tells me that the ZERO approach using "normal" taps from the amp would be the better choice, if for no other reason than having greater latitude in choosing an amplifier.

Once again, I find myself in a discussion that exceeds my experience and level of expertise but realize that just because I can't hear anything above about 8000Hz doesn't mean that those frequencies above that level don't contribute to distortion. However, in regard to those "shunt approaching" frequencies described, there are no musical instruments, at least in the base harmonic, that come near 20KHz. If my understanding is correct, then, does this mean that using the 4 ohm tap with the electrostatics may be acceptable at low to moderate volumes?

^^It might be, but when you use the 4 ohm tap of most tube amplifiers, the output transformer often has a loss of bandwidth at both extremes and some are better than others. The ZEROs take care of that problem by allowing you to use a higher impedance tap where the transformer is more efficient and the amp makes less distortion.

While fundamentals of instruments don't go that high, harmonics of them certainly do.