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
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:

http://www.ebay.com/itm/RAYTHEON-12AX7A-MATCHED-PAIR-BLACK-PLATE-HALO-GETR-FOR-BALDWIN-TEST-NOS-ECC83-2-/230745104890?pt=Vintage_Electronics_R2&hash=item35b97ae1fa#ht_1166wt_689

(no affiliation to seller)
PS, if your price is right I will pick up Agon fee. I don't quite know how to do that , but I wll find out provided either of you want to sell the Sylvania or GE.