I push my SL-3's with a Sunfire Cinema Grand, using the 3rd and 4th channels on the amp for the woofers (bi-amping) with great success. The amp is relatively inexpensive, incredibly flexible and power output is phenominal. Using the bi-amp method you put nearly 800 watts to each speaker. I am currently looking for a tube pre to "warm up" the sound. I think most SL-3 owners will agree the speakers sound even better with tubes up front.