“Left transistors 25 years ago, for sonic reasons!”
25 years ago, that was true. Today, not so much. Pass Labs do an amazing job on Sound Labs, without any of the hassles associated with tubes. Wolcott amps do a great job with Sound Labs, but I’m not going back to tubes.
The Parasound JC-1 amps do a very competent job, but lack soul.
A great preamp is an asset in any system.