Yuri, Read the reviews in Stereophile on line about the KSA 50S - they describe the differences between it and the original KSA. It seems that the reviewer thought that the original was a warmer and more rounded amp, more musical if you will. The KSA 50S was a bit more hifi (my terms). Anyway, read it.
Krell KSA 50 vs. todays ss amps?
I have never heard a KSA50 but they get great press. Has anyone who has heard one compared it to say the Halcro( which also seems to get great press) or to any of todays ss amps, like Edge or Mark L etc.