Recommendations for a "summer" amp?


Living in a hot southern climate I'm considering acquiring a 2nd amplifier for summertime use as a backup to my Pass Labs amp which runs quite warm. Solid state, cool-running, fairly recent vintage (don't want to invest in service) with a used price somewhere below $800. I had a good candidate in storage but I gave it to my brother so I need some recommendations. My system is comprised of an ARC tube pre and B&W Matrix 800 series speakers.
abrew19
I live in Antarctica.

My favorite Summer amp is the Krell KSA-250.

Even with all the windows open it keeps my living room a very comfortable 68.4 °F.

On a slightly more serious note: If you have budget, the Odyssey Stratos have about 30% more juice than the Kartagos, which your Matrix 800s will gleefully put to good use.
The Luminance Audio KST-150. It is a high speed, high bandwidth mosfet amp. It runs very efficient like a digital amp and is cool to the touch, but its sound will blow any digital amp out of the water.

In fact you will probably not want to put your Pass amp back in once hearing it, a true giant killer. It needs a week of break-in, more so than the typical new amp.

http://www.luminanceaudio.com/
My "summer amp" is the Marantz AVR in my HT system. The sound quality is good enough considering that the noisy AC unit is running full blast anyway, which trumps serious listening.