HARMAN/KARDON signature 2.1 5 channel amp upgraded The GOOD about this amp. I have spent a lot of money on this amp upgrading the internal parts. All the caps have been replaced and up sized/ the main rail caps have been upgraded from 12,000 uf to 18,000 uf. The main power wire was removed and upgraded with a 12awg plug with a ground. This amp has always been cooled with forced air cooler. Amazing output and sound quality. The specs Im listing are stock this amp will do 10-15% more easy. 100 watts per channel x 5High current, ultrawide-bandwidth designLow negative feedback and low harmonic distortionAuto turn-on triggered from HK Signature 2.0 preamplifier/surround processorFanless cooling designFor those seeking home theater performance a cut above the ordinary, the team of Harman Kardons Signature Series 2.1 multichannel amplifier offers superior sound, sophisticated ergonomics, and outstanding build quality.Manufacturers often slant their power specifications to make a given product appear more powerful than it is. Harman Kardon, however, doesnt need to fudge its specs for this dynamic, well-behaved, and (for its quality) reasonably priced five-channel amplifier. Some amplifiers actually decrease their power output when driving lower-impedance speakers; the Signature Series 2.1 gives you an honest 100 watts per channel (wpc) into 8-ohm speakers and 150 watts with 4-ohm models across the full audible bandwidth, with less than 0.03 percent total harmonic distortion when all channels are driven. The BAD News about this amp. Channels 2 & 4 have stopped working. This is a 3 channel amp right now. I have unplugged the power leads to those bad channels to stop any more damage from happening. Could be something small i have not had it checked out. I only needed it for 3 channels for lcr duty. Thats all the bad news there is. This is amazing amp and anyone would be lucky to own this amp. I will be starting the bids low. Good luck.. This item is sold as is and no returns I have listed whats wrong this item so there is no shock when u get it.