Low volume music

With out a doubt I'd check into Quad esl's...

In my experience, the best for low volume listening are slightly-bright speakers that have very good analytical power and sensitivity. The amps don't matter as much as the speakers do so you need to tackle the speaker choice first. Triangles are a great candidate. I have never heard any speakers sound as good as they do at low volumes.

Tube amps are a good choice as well. I find that SS amps' lose bass at low volumes whereas tube amps don't. The Fletcher Muson curve will tell you that human hearing needs extra bass at low volume to get a linear response. So keep that in mind.

Arthur

As some have already pointed out. Bass is an issue. You need to use the equivalent of a "loudness" button at low levels or you will lose the bass response due to reduced hearing sensitivity.

If you refuse to have any tone controls whatsoever (often an audiophile affliction) then you need to find a speaker with warm resonant harmonic distortion in the bass. You could also look for a tube amplifier or something with high output impedance that will boost the speaker at the woofer resonance point (more bass) and increase harmonic distortion (you can create this by overdriving slightly a tube amp without sounding too loud. SS amps can't do this as they sound awful when overdriven).

Remember that sounds seem louder or better defined if they are rich in harmonics...perceptively this means that the tone or note sounds "fuller". You lose some accuracy in terms of true timbre of the instruments but you gain in having a system that you can enjoy at quite low levels without disturbing others.

Listening at low volume is a high priority of mine also.
I'm using a BAT 300X-SE with Thiel 1.6 and Harmonic Technology Pro-9/Magic-I.

The low noise-floor of this system is remarkable.
The BAT maintains musical integrity all the way down to "1" on the volume control.

I find that SS amps' lose bass at low volumes whereas tube amps don't. The Fletcher Muson curve will tell you that human hearing needs extra bass at low volume to get a linear response.

Here's a perfect example of how ignorance spreads fast in free sites like Audiogon. It should be obvious that the Fletcher-Munson curves have nothing to do with the type of amplifying device, but rather with the sound pressure level.

Regards,