Paul, what are your feelings on a hybrid unit? ie. Op amps in the front end, and a tube on the output.
Bernie.
In my experience, hybrids have never sounded as good as tubes. This goes for power amps (solid state last stage) as well as small-signal preamps (opamps, or even just a FET, at the input). I have not heard everything, and am still willing to be surprised, but it hasn't happened (in this area) yet.
The same goes for feedback and transformers. Feedback was easy, it's been clear to me for a long time. I do hear that tubes with feedback sound better to me than solid state with feedback, but zero feedback tubes sound even better. (For my taste, single ended sounds better still, even compared with zero-feedback push-pull DHTs - but at least I do respect different opinions on that one!) But it took me a long time to agree with Doc B. on transformers. I love them, but have to acknowledge that if you can get away without them it's better.
Sometimes these things are necessary - we've had many many years of great satisfaction and success with the Foreplay, which has a cathode follower, i.e. feedback. And the big Bottlehead speaker system has many cathode followers in the active crossover. But now that we have tried the 300B direct-output preamp there is no question to my ears that it is better. I'm sure we will compromise these principals off and on in the future, but I'm always looking for ways to do it without compromise.
Interestingly, at least to me, is that a solid-state current source as a plate load does seem to sound better than a choke. The bigger the better for the choke, but the current source still "wins". So, I have some rules of thumb as above, but there is no substitute for listening, and I continue to learn new things.
