Rolled some 12ax7's recently...

Hi Clipper,
I have the BB 12ax7's in the phono stage, a BB 12at7 nearest the transformer, 2 Sylvania 12at7's near the can caps, and an unknown old stock 7025 in between (near the 6v4 rectifier).

The pre-amp sounds fine on tuner and both aux's, and of course, super fine on phono. I have repaired mine as many of the old Wima caps have dried out and wasted away.

I have also used the BB's in my Dynaco Pas3x and have found the same results as I previously described. The Fisher is not as forward sounding as the Dynaco, but it is, oh, so much sweeter! I was happy to see some Fishers selling on ebay for more than $450 in the last few months! As I recall, one of those was the 400-cx, which has a better following, but the other was a plain old 400-c. I have the 400-c. I like it and can't wait to get my Koetsu re-done -- should be mid-range luscious delight!

In my phonostage (Viva Fono) I've tried a number of different 12AX7 variants. The Mullards sounded a bit veiled (muddy) for my particular application. In a friend's Tron phonostage, Mullards actually sounded oddly phasey.

I liked the sound of 5751s -- neutral, reasonably detailed and open on top. I did not notice a loss of gain, but, I wasn't looking at gain because gain and noise are not issues with my phonostage.

Telefunken 12AX7/ECC83s were also very good in my phonostage -- quite detailed, extended top and good harmonic density without being muddy sounding.

The Telefunken ECC803S is a very different animal from the other 12AX7s I tried -- incredible clarity and detail and explosive transients. It sounds a bit lean (less upper bass) and perhaps clinical, but, I made other minor compensating adjustments (primarily to VTA), and it is the very best tube for my application.

However, the ECC803S is WAY more expensive than the competition. For the money, a good pair of 5751s are hard to beat.

RE what Larry just said about the premium TFK, I have a general 12AX7/5751 question/poll(?) for those familiar with both (hopefully, but not necessarily, in the same piece of equipment ;-)

In his famous "Tube Lore" article on AA, http://www.audioasylum.com/scripts/d.pl?audio/faq/joes-tubes.html Joe asserts that he could never really find a 12AX7 he liked. He lists some preferences, but compared to his favorite 5751's, he finds all 12AX7's "grainy" (I think his word was.)

I maaaybe understand what he means. However I've rolled many different 12AX/AT7's and 5751/6201 in my McIntosh MC275, and like Larry, I've learned that to have blanket prejudices/preferences may not lead to the best choice - my love for the GEC A2900 being a perfect example (I never would have tried it if I'd decided to only go with 6201's.)

So does anyone agree with Joe's take on the issue: that 5751's are better across the board than 12AX7's? Just curious ;-)
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I don't what is meant by the statement that 12AX7s are "grainy." I sometimes wonder if "grainy" is sort of the opposite of "fluid" or "smooth." Sometimes, what some others describe as smooth or fluid, I think of as being "soft" and a bit "muddy." The "muddy" quality I am talking about is a bump up in upper bass lower midrange that tends to obscure (or soften) upper frequency detail. Perhaps this detail is the "grain" being referred to; its hard to guess what these terms mean. So much is dependent on personal taste and system application, I don't think any generalizations can be made that one tube is better than another across the board. That is why, in my prior post, I emphasized the fact that my observations pertained to MY system.

One thing I forgot to mention in my prior post. For the Tron phonostage, the best alternative turned out to be Amperex Bugle Boys, at least in my friend's system (the consensus of several listeners). We did not try the ECC803S for this particular trial. I don't recall what current production tube the Tron came with, but, it is utter crap compared to the old alternatives we tried. The Tron was extremely sensitive to tube choice. I suppose this is a tribute to how revealing this phonostage can be.

Thanks Larry. Anybody else want to chime in?

I'm listening to horns today (recordings), so maybe that should be 'honk' in ;-)