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.
i just had a rare stroke of luck! it`s sunday evening here, and all my neighbours are out! i put on dave gilmours cd on an island and played it above my normal listening levels and as a real bonus, for the whole of the cd not even a car drove past let alone a bus! how amazing are these kt88-z`s!!! i`ve just been blown away by them! the bass is tremendous and so beautifully rounded. on one track ("take a breath") the bass growled. the atmosphere on each song is amazing! the tones dave gilmour gets out of his guitars are pure magic. my favourite tracks on this cd are the last 3 tracks "smile" "a pocket full of stones" and "where we start" are in a different league through these tubes. closely mic`d voices through this system are scarily real!!! on "a pocket full of stones", the start of the track is just gilmours voice accompanied by a piano, this sounds truly haunting now. incredible amounts of atmosphere and emotion and he sounds so isolated. his voice fills the soundstage and you can pin point the location of his voice. on the last track "where we start" his guitar has a smooth warm feel and he has that amazing ability on certain notes where needed to get that sheen that hits the spot with all of us and these kt88`s pull that off with such ease. there`s not only massive amounts of information on a disc that these tubes can extract but also massive amounts of information within the notes being played themselves. you seem to get it all, texture and tone!

on saturday i likened listening to these tubes to having the main lights off, candles on with a warm fire glowing, well i stand by that even more so now. it`s like watching a dark scene on a bluray disc through a stunning television being able to pick out all of the pleasing brighter detail while still being able to see all the various darker details and shades with the greatest of ease. these are remarkable tubes, and to think they`re only 35 hours old!!! how much better are these gonna get???!!!
need some advice. there`s a pair of SYLVANIA JHS 5751 BLACK PLATE TUBES triple mica square getters for sale fairly cheap. are these good tubes to fo for? they don`t have gold pins, just normal ones. thanks guys
Yes, those are good tubes I'd snap them up if I were you. That being said, you seem to prefer the 12AX7's to the 5751 in your setup (though that might change when your Treasures have completely broken in). If you get them and decide you still prefer the TF's, you'll be able to find someone to take them off your hands (I would).
****i did some extended listening yesterday evening at a much more decent sound level. i found the ge 5751`s a little too warm for my set up. all the detail is there just too warm. my amp is already on the warm side so i guess the ge`s were too much for it.**** - Grayf

I would try these:


(no affiliation to seller)