Studio/Performance Amps for High-End Systems?


As a practicing (hobbyist) keyboard player and audiophile, I am familiar with why one would not use a guitar amplifier for a keyboard, for example. But, I notice that some of the finest brands of high-power power amplifiers for recording studios or live performances (QSC, Crest, Crown and more) cost hundred or thousands of dollars less than high-end "audiophile" power amplifiers of similar or fewer watts/channel. The specs of these musicians' amps, designed to play 20-20K full-range sound through very low impedances (often as low as 1 ohm) seem to equal those of, say, a McCormack, Classe, Krell amp.
Is there something I'm missing here? If one needs 500 wpc or more, why buy a McCormack DNA-500 for $7K when you can get a QSC with 800 wpc into 8 ohms, capable of driving a 1 ohm load, for $2500?
toxrtp
ATC, Bryston, Manley and EAR make amplifiers suitable for professional and audiophile applications. Also didn't Boulder start out making pro-oriented amps.

I agree with the tone of Shadorne's comments about audiophiles wanting a softer presentation than what is useful in a studio environment.

As an aside, there is a school of thought that takes the position that power amplifiers, while important, just aren't that critical to getting high quality sound. Peter Walker of Quad and Siegfried Linkwitz are prime members of that school. Historically, at least for solid state designs, amps didn't become important until Apogee came out with their sub-2 ohm speaker designs. It was then that you saw an explosion of pricey, high current designs and people started to talk about how amps sounded.
Onhwy61- And which of those companies offers a 500wpc power amp for $2500.00?(Read the original question) I know beyond doubt there are a lot of people that are happy with a "softer presentation" or a "warm, sweet, fuzzy, tubey" or whatever sound from their equipment, or that can be satisfied listening to PA gear. I'll never tell someone what makes them happy in their listening room is wrong. Like I said: Enjoy the savings.
As a fellow pianist (and keyboardist/electronicist), I'm interested in this, but from a slightly different angle: I'm interested in using home speakers in performance. The ultimate goal is a higher-quality sound that fits in acoustically with other instruments, even though the source may be a keyboard or laptop. This motivation has resulted in things like this hemispherical speaker:

http://www.electrotap.com/hemisphere/

I'm wondering if a Ohm Microwalsh, for instance, could be driven with a small instrument amplifier (Acoustic Image?).

Any thoughts?
Why? There is definitely a compromise using an instrument amp. The little things like RCA to 1/4 inch adaptors for the jacks will degrade the sound more than you think, especially balanced to RCA adaptors (different impedance).

I owned some fairly sizable clubs and have played with Crown, QSC, Crest and more. Amazingly abusable but that's it. Yes, if budget is an issue, a $300 used Crown will give a lot more volume than a $300 audio amp but at a great expense...Inexpensive studio speakers are the same way, lots of volume but harsh and lacking in the very highs & lows and definitely not smooth. Yep, you can get custom designed ones from companies such as JBL which cost a fortune but are amazing sounding.