My $.02 on your using Tung Sol Round Plate in a tube buffer. I think it is a shame to use those precious nearly extinct tube for that purpose. A tube buffer is just that, a buffer, where the tubes aid in matching impedances between to other pieces of gear. In your set up I failed to see a real need for a tube buffer at all.
Instead get a 6SN7 based preamp if you really want to hear what those extremely valuable tubes can do. Try them in a gain stage if they are not burned out or microphonic. If microphonic they can also have a significant but less well heard impact as driver tubes.
Another thought would be to buy an integrated with a tubed preamp section although I don't know any off the top of my head any hybrid SS integrated that uses them as the preamp gain stage. Many all tube integrateds use them as drivers or possibly phase splitters and inverters but not usually.
Any of those chioces will have a big impact on your sound. As for biamping I think if you get the right external active X-over you can use SS amps for the woofers and tube amps on top. This is a logical but evidently difficult approach to improving sound.
Instead get a 6SN7 based preamp if you really want to hear what those extremely valuable tubes can do. Try them in a gain stage if they are not burned out or microphonic. If microphonic they can also have a significant but less well heard impact as driver tubes.
Another thought would be to buy an integrated with a tubed preamp section although I don't know any off the top of my head any hybrid SS integrated that uses them as the preamp gain stage. Many all tube integrateds use them as drivers or possibly phase splitters and inverters but not usually.
Any of those chioces will have a big impact on your sound. As for biamping I think if you get the right external active X-over you can use SS amps for the woofers and tube amps on top. This is a logical but evidently difficult approach to improving sound.