What makes you build a system around an amplifier?

Sean:

Really good question! I’m afraid I don’t know of strong research in this area, so I can only guess that in some ways, a good amp does not ruin:

• Crosstalk
  
• Phase
• Amplitude
• Channel matching
  

It may be some amplifiers actually change one or more of these values from the ideal. It has been shown that dips in the 2.4kHz range in speakers can enhance the perceived imaging, so perhaps a very colorful amplifier also plays around in the frequency and time domain.Or perhaps interactions with certain speakers pushes something in the frequency or time domain around just enough. :)

It may be something quite counter-intuitive, like for instance, rolling off the top octave. I don't know enough about imaging science, but I find the idea of Head Related Transfer Functions fascinating, and wonder how they apply to tube electronics.

Hopefully some one will jump in and tell me where the state of the art research is!

Best,

E

Many tube amps do not have a decently flat frequency response under real loads (just look at the Stereophile graphs - they are often horrible). Often their response is tweeked to appeal to the subjective audiophile who thinks his hearing can beat any audio analyzer from the likes of Audio Precision or DScope.
Moreover, image and ’air’ can be quite delusional/artificial properties. Just go to a good concert hall and listen to a symphonic concert. Imaging there is usually far less precise than what you hear at home from your audio gear.

Moreover, image and ’air’ can be quite delusional/artificial properties. Just go to a good concert hall and listen to a symphonic concert. Imaging there is usually far less precise than what you hear at home from your audio gear.

I would hope that at home, we have a much better seat and acoustics.  

Seat maybe, acoustics never. The difference does pose the question what the aim is of good audio equipement: the (impossible) recreation of a live event, given the physical limitations, or something else.

Do you even listen to music?

:) I have about 8,000 LPs and not one is Nina Simone, so yes...

Many tube amps do not have a decently flat frequency response under real loads (just look at the Stereophile graphs - they are often horrible). Often their response is tweeked to appeal to the subjective audiophile who thinks his hearing can beat any audio analyzer from the likes of Audio Precision or DScope.

This statement is not accurate. Most tube amps are intended to act as voltage sources and so do quite well on such tests. But many tube amps are not intended to be voltage sources out of intention- and of course part of that is they are not intended to be used with speakers that expect that amp to be a voltage source. The 'tweaked' statement in the post is entirely false. This is a topic worthy of its own thread.

The difference does pose the question what the aim is of good audio equipement: the (impossible) recreation of a live event, given the physical limitations, or something else.

The best model I've come up with to describe how a two channel system works is to imagine that the room and its stereo is a sort of time travel machine ala Dr. Who, that will allow your room to be 'grafted' in the performance space of the original event. For this reason you cannot hear what is around you, but you can hear what is in front of you just as if your room was hovering in space in front of the musical event.