@noromance My experience was similar to @mulveling . But, it's definitely speaker-dependent. Before the new speakers, I had B&W 803N and then Revel F208. For both of those, the KT150 was better than EL34 overall, although I'd say that the EL34 did have a sweeter midrange (or it seemed that way because the bass was less punchy). KT150 retained a lot of the flavor of the EL34, but had more punch in the bass, well balanced across all frequencies, and IMO better control of the speakers. When I moved up to the F228Be, the KT150 sounded good until I started to compare. The 7581a are really nice (better than KT150 overall), and really close to the EL34, especially in midrange. But, somehow the EL34 seemed to have cleaner, deeper bass, and clearer, crisper highs. All of that was definitely improved further when I got the TungSol EL34b. And, on top of tha, they have that liquid midrange wonderful sound that EL34 gives you. It's just better all around.
Again, it was a completely different outcome with different speakers. So, you have to try for yourself. If you still have EL34 and 7581, do a comparison and see which you like.
Interestingly, @mulveling , I didn't like the KT120 nearly as much as the rest of these. I found them to have a certain "glare" in the midrange, especially around vocals. For example, Mark Knopfler's voice always sounded a little "fuzzy" around the edges. With all the others, that effect is completely gone. But, again, it is probably speaker dependent. I didn't have any KT120s to try with the F228Be speakers, so I can't validate. If it works for you, then spin some vinyl (or shiny discs) and enjoy the music!
Again, it was a completely different outcome with different speakers. So, you have to try for yourself. If you still have EL34 and 7581, do a comparison and see which you like.
Interestingly, @mulveling , I didn't like the KT120 nearly as much as the rest of these. I found them to have a certain "glare" in the midrange, especially around vocals. For example, Mark Knopfler's voice always sounded a little "fuzzy" around the edges. With all the others, that effect is completely gone. But, again, it is probably speaker dependent. I didn't have any KT120s to try with the F228Be speakers, so I can't validate. If it works for you, then spin some vinyl (or shiny discs) and enjoy the music!