12BZ7/12AX7 vs. 5751

"I just don't get the whole tube rolling deal."

I must respect your opinion since you are a dealer, with lots of experience I presume. I will put aside some thoughts I might have, being on the other side of the coin.

But I would like to understand your recommendation since you went directly to the speakers. Why not the source, the amp, cable changes, room or power source treatment ? Can you explain why go immediately for an expensive solution ?

5751 sound thin, if you like a more solid state sound then go 5751's. Joe's Lore is what he heard in his system with his ears and his likes. Nothing wrong with that, but it does not make for in stone what tube is the best for your system and your ear and bias.

surprising comment " i just don't get the whole tune rolling deal" given sounds real audio that you sell tube gear - try it you might be amazed

Not getting the "whole tube rolling deal" is like "not getting the whole appreciating differences between things deal." Also, I'm a believer in 7025s as a 12AX7 swap, although results may vary. Is an accurate and full range tube tone a "SS" sound? This term is bandied about by term bandiers suffering from adjective deprivation. I prefer my music to sound tonally correct using my extremely refined ear, impeccable taste, serious demeanor, and finger burning tubes glowing for my amusement and aesthetic needs. Both ears actually, especially when they're clean-ish.

I can't comment on whether 12bz7 is a substitute for 12ax7/5751 however if it is my advice would be take advice only from those who have experience of your amp or go out and listen for yourself.

For me Sylvania 5751 are excellent, better than any 12ax7 I've tried but in another implementation they may not work at all.

Can be good fun exploring different tubes though expensive and a good measure of frustrating