Inter-M R-500 2-Channel Amplifier

I recently purchased a used sample of this amplifier to improve my surround system. Mainly it'll be used in a "Pure Direct" mode playing only on my Apogee Centaurus Slant 6 front speakers.
After only a few hours of listening I'm impressed with its power and control. It plays the entire register with detail and ease. My Yamaha surround reciever couldn't at all reproduce music with electrical bass in a realistic way. Now I hear a clear note and the sound of the finger making it. The largest improvement I've noticed so far is a tighter and more defined bass. I'm sure more are to be revealed within shortly ;-)