Add Sub Woofer

Personally, I'd put an active x-over like the Marchand or NHT (if you can find one) between the preamp and power amp. I'd also think about adding a digital room correction unit for the subs (SVS/Audyssey or Velodyne SMS-1) between the bass output from the active x-over and the line-input to the subwoofer.

BTW, I had a KSA 50s for years and it still ranks very high among my favorite SS power amps.

Marty

I had a KRC2 prior to my KCT. I would hook the amp VIA XLR (balanced) and use the RCA's to the sub if it has that type of connectors. Good luck, John

IMO, I would sell the speakers.Take that money along with what you will spend on a nice sub and upgrade to better speakers.Your speakers are your weakest link...