Any help on Threshold s550e amp?

I listened to an S-500 upgraded to a 550e, and found it to have a dead, airless, lifeless sound, especially the high end. Perhaps this unit was not representative, I don't know, because the S550e certainly had high ratings.

The heat sinks were very slightly warm on this unit. Does your S300 run cool like that? I think you should try some more current amps, like the Simaudio, McCormack, etc. If this is from a dealer, I would make comparisons with this other equipment.

Jdh, I would compare the Threshold to the Mac 352, because the Mac is a very good amp with a large soundstage, good bass, nice body to instruments, a little soft on top. I'd be interested in your impressions of the two amps. If the Threshold compares, buy it.

It is now obvious to me that the S500 I heard, that was updated by a Threshold technician to an 'e' series & supposedly biased heavily into class A, was a lemon. It sounded dead & dull, and it ran so cool, I knew something was not as it should be.

Let us know your audition results.