12ax7 vs 5751

I am impressed with your choice of 6SN7s. I really like the Brimar CV1988 GTY. See if you can get some Sylvania GTs or Ws as well for 6SN7s. Given your choices with them I would definately recommend that you look into 5751s.
I find 5751s to be more defined and yield better soundstage in my applications. I agree that there are more good ones floating around than most NOS 12AX7s. I also say you should look into it- as no one can assert with certainty what you will like. I have a hunch you will like them. Sylvania triple mica BP are prolly the best but failing that, try some TM BP RCA white lable, Raytheon in general, (yes windmill getter but they are rare) then perhaps lastly GE with some special GE vintage exceptions. The militery versions of all are good.

wow thank you guys for the wealth of information. the psvane tubes i`m currently using sound just fantastic but i`m sure they`re limited in the soundstage width and depth. i`ve played around with all the other tubes and so far the brimars have had the best results in the soundstage and tone but i`m looking for more depth in the soundstage. thats really why i`m looking into the 5751 range of tubes. i`ve read good things about the soundstage they throw out. tonally i`m extremely pleased with the range of tubes currently in my amp but like everyone out there, if the sound can be improved upon then why not indeed. you only live once! i`ve been considering getting some sylvania 6sn7gt`s too to mix with the brimars. i think the wgt`s will have too much upper attack for my system but i have my eyes on a matched pair of sylvania bad boys. the gtb`s that i`m using right now seem to go hand in hand with the brimars tonally. voices are amazing! i tried the brimars with a matched pair of rca vt231 grey glass tubes but it was an awful match. too much warmth to the point of making it sound dull. i had such high hopes too for this matching.

joes tube lore is making for a very interesting read! i think i`m going to be having a lot of fun experimenting here with different tubes.

i`ve got to say too......i`m having the time of my life listening to different tubes. this being my very first tube amp! i`m impressed at all the different qualities each tube brings to the amp and all the fine tuning that can be achieved. the amp sounded good enough with the standard tubes that came with it but the amp was secondhand and the tubes were very noisy!

also when the psvane tubes were breaking in i was shaking my head in disbelief in the 1st 5 to 10 hours! the sound changed quite a few times! everytime sounded good with the exception of a couple of times the sound seemed to come out of complete darkness and that blew my mind! wish i could get that particular sound back! but thats not really a complaint as i love what i`m hearing now

another thing i must add......i seem to sit there now listening to music with a big stupid grin on my face most of the time! what a way to escape the stresses and strifes in this life!

Another thing about the 5751s is that they were designed for the military, so they are very rugged, long-lived, and low in noise. I had the great fortune of picking up a pair of NOS Sylvania Gold 5751s about 14 yrs ago and they now reside happily in my Jolida phono preamp.

another quick update and the best one yet! when i was tube rolling i tried the brimars and the rca vt231 together. i had the brimars in v1 and v4 and the rca`s in v2 and v3 on my amp. they sounded pretty awful! well i didnt realise that swapping them around would bring a massive difference! this weekend i put the brimars in v2 and v3 and i put the rca`s in v1 and v4. wow the sound is so clear!!! i wish i discovered this when i first tried them. i`ve lost the warmth i had with the brimar/sylvania pairing but now i can see much further into recordings. all the subtle sounds that were hardly noticable are now much more prominent. recordings are very clear sounding and tonally more realistic. the soundstage is solid and believable. the detail is amazing! the bass is very full, detailed and has this extra punch. my amp sounds completely different now! i can`t believe how much clearer the overall sound is. i heard the most subtle details that i`ve never heard before on david gilmours cd on an island this weekend just gone and the sound effects throughout his cd are just incredible! listening to adeles cd 21 the 1st 2 tracks now have so much drive. the seperation of individuals is just awesome too. i could still do with more depth to the soundstage though. i really am sure it`s the psvanes restricting the depth of the soundstage but i must say, changing the brimars and rca`s around have hugely widened the soundstage though. for the first time the sound goes way beyond the width of the speakers which i have to admit messed with my head at first! anyone that has this amp really ought to try out the brimar/ rca vt231 combination. this is seriously good stuff!