12BZ7/12AX7 vs. 5751

While I have never used a 12Bz7.I have tried NOS low noise, matched,(read expensive) 5751 tubes in place of the 12Ax7 that were stock in my Tron preamp.After about one month of listening I placed the 12Ax7 back in the Tron.
My conclusion was that the 12Ax7 gave more body to the music,with better dynamics,separation of musicians and wider stage.Others may say that my conclusion is wrong Joe's Lore) but this is what I heard in my room with my components.YMMV

Sam, thank you for the backup. Clearly one of those salesmen who wonders why he never sells anything.

I went to my favorite secret old TV store with thousands of tubes lying around looking for a pair of 5751s, but he didn't have two. However, he did have an NOS pair of GE 6BQ5s which - probably because they're fresh - are a bit of an improvement over the old Mullard EL84s. So... you never know what you're going to find.

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

"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.