I have am audiosouce 5.1 monoblock amp 100watts into 4ohms. I have used it to drive an SVS CS sub with great results . It has a large torroidal transformer with discrete ouput devices and oversized capacitors. This amp is 2 ohm stable and did a better job of driving my sub than a more expensive marantz ma500 amp, I had previously. I will double box . I have original box and manual. This amp is in perfect operating condition. I accept paypal or money orders.