This is a 150W/ch. into 8 ohms, 300W/ch. into 4 ohms stereo amplifier. It is not the MKII version which is $1000 more expensive. The amplifier is in excellent condition visually and works perfectly. I am the original and only owner of this 4 year old amp. It is a "hybrid" amplifier, which as the ads say combines the virtues of both tubes and solid-state, with none of the drawbacks. The amplifier is German designed and Chinese made. Thanks, Roy
P.S. I apologize folks. This is the SP-331 amplifier, not "SA." Thanks to all for the notification. Growing old stinks!