[MichiganMike]

I agree the McIntosh amps are overkill, but the SongTowers now sound like a much more expensive speaker.

I had the pleasure of auditioning SoundScape 10 speakers with Jim Salk over the weekend in a very large room, so I now have a better reference point.  (Thanks again, Jim.)  This was potential overkill from the flip side as the SS 10s were powered by an amp with a MSRP about 10% of that of the speakers.  The resulting soundstage, bass extension and clarity exceeded my SongTowers by a wide margin, but low level detail was where the limitations of the amp were most apparent in my opinion.  I look forward to pairing SoundScape speakers with my MC501s and hope to hear a similar improvement to that I heard with my SongTowers when upgrading amps.   
 

[MichiganMike]

I have now paired a McIntosh C48 preamp with the MC501 amps.  This combination extracts even more low level detail from the source and projects an exceptional soundstage from my SongTowers.  The bass response and clarity is also enhanced.

While this is even more of an excursion into overkill, my SongTowers have never sounded better.  My wife would be even happier if I was not in the process of replacing the SongTowers with SoundScape 10 speakers.