Herman, while you are largely correct, at the first VSAC in Washington there was a demonstration of the sounds of different output tubes. The had a single channel rig that would allow swapping output tubes. The 45 tube won the greatest support for its sound.
My experience with the 300B, however, suggests the fundemental difficulty with the question. As I said, on many of the first 300B amps that I had or listened to, the tube sounded very good in the midrange but without extension at both ends. The Exemplar and Reimyo amps, however, proved that the tube could sing. One used a solid state supply and the other a classic tube supply.
My Reimyo was delivered with '96 production WE 300Bs, but substituting real '60s WE 300Bs proved to give enormous benefits in openness and transient attack. Nothing else was changed.
My experience with the 300B, however, suggests the fundemental difficulty with the question. As I said, on many of the first 300B amps that I had or listened to, the tube sounded very good in the midrange but without extension at both ends. The Exemplar and Reimyo amps, however, proved that the tube could sing. One used a solid state supply and the other a classic tube supply.
My Reimyo was delivered with '96 production WE 300Bs, but substituting real '60s WE 300Bs proved to give enormous benefits in openness and transient attack. Nothing else was changed.