I will now also recommend the Yamaha P3500S pro audio amplifier for home use. It is not quite as powerful as the EP2500(EP2500 is 450x2@ 8 ohms, 650x2 @ 4 ohms, 1000x2 at 2 ohms), but the Yamaha needs no fan replacement to be silent. The Yamaha(350x2 at 8 ohms, 450x2 at 4 ohms, 20-20khz) has a fan, but it will not cut on unless the heatsinks hit 50C or greater. I tested the P3500S at 93dB a 2 meters, measured, on two 4 ohm nominal speakers for 15 minutes, then immediately increased the SPL to 98dB at 2 meters, for another 15 minutes, and the fan never activated. I quickly removed the amp cover after the 98dB test and measured the heatsink with an infra red thermometer and the heatsink was only 42C. Not even close to reaching the temperature needed to activate the fan, and this was at ridiculous SPL levels. This was in an ambient temperature setting of 20C(68F). The speakers used were rated at 88db/2.83v/1M sensitivity.
The EP2500 is best to use if you want to drive really tough loads, as it's designed to drive 2 ohm loads. The Yamaha is designed to drive 4 ohm loads.
I will soon test the smaller Yamaha, the P2500S, under the same manner as the P3500S to see if the fan will come on.
-Chris