12ax7 vs 5751


hi all,
i need some advice. i`m very new to tube amplifiers and i`ve been doing some tube rolling.

i currently have a pair of grant fidelity matched psvane 12ax7t`s in my amp which sound fantastic.

what i`d like to know is which are the better tubes, 12ax7`s or 5751 tubes. i`ve been looking at forums and there are folk out there that say 5751 tubes are better than 12ax7 tubes.

can i have your thoughts on this please and also which are the good 5751`s to go for.

i really like the psvanes but if they can be bettered i`d go for it as my next line up of replacement tubes.

my amp is a yaqin mc100b. the tubes i have installed at the moment are.....
2 x psvane 12ax7t`s
2 x brimar 6sn7gty/cv1988`s
2 x sylvania 6sn7gtb`s
4 x electro harmonix kt88eh`s

many thanks in advance guys.
grayf
many thanx for that info cymbop. thats pretty interesting information there. it`s well worth me investigating the 5751`s in the future
It's not possible to generalize one as better than the other. They are interchangeable, though the 5751 has a gain rating that's less than the 12AX7. I run 5751s in my 12AX7 slot and can hardly discern less volume. Because the 12AX7 is so common, it's more sought after and as a result old stock models are more expensive. 5751s fly just a little under the radar and so you can get good ones at a better price.