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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
xti16
1,525 posts
 
Last the Ei KT90's used to be my least favorite output tubes. Only after swapping out the drivers (2 Rca 12at7wa and input 1 Sovtek 12ax7) with Gec CV6091 (military version of the A2900) and Rca triple mica black plate 5751 did I really start to like the Ei's. So I believe with the right combination of tubes anything can be made to sound better :).
So have fun
ebm
9,311 posts
 
Not the same.
onhwy61's avatar
onhwy61
5,215 posts
 
Anyone using 7025s?
mcpherson
174 posts
 
Grayf
It is good to hear someone enjoying the process instead of simply obsessing...
Are the Telefunken12ax7s just a standard issue or do they have different ones?
mechans
3,048 posts
 
I have tried 7025s only briefly. I found them to lack the delicacy transparency and detail the 5751s gave me. I didn't try many because they seem to be a favorite of the Guitar amp guys who drive up price and make good ones quite scarce. I know I tried RCA but don't recall others. The major differences in Telefunkens are smooth vs ribbed plate and early vs later. Also the holy grail of 12AX7s is the ECC803S by TFKN. I own some 802 and 801S but sadly never lucked into or afforded the 803S.The early smooth plate 12AX7s seem to be the preferred tube but not by everyone.
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