An update in case anyone was interested. I am now powering my S2's with a 25 watt amp. I wasn't sure how it was going to turn out but they sound great, maybe even better than my main system (with a power amp).



BTW, I started with a pair of 200's for convenience - new stereo in new room. I've had 200's as surrounds for years but never really ever have just listened to them. I have to say I was impressed. But they still went back as surrounds and moved the S2's in when everything was ready. I could totally see having a nice 2-channel system and using 200's.