CAT Ultimate/Tube rolling

true, C123666. however, even w/ NOS the skeptic in me does not expect 100% life owing to the fact that these tubes are 30-40 yrs old & the vacuum is probably compromised some. If i get full life from them, i'm very happy & it's like icing on the cake but I go in w/ the mind-set that i'm going to get less life from them.
Anyway, that's what I meant to indicate in my prev post.

I guess we need a new term UOS for used old stock!

Hey Bombay - any news on the Mullard 12ax7?

Hi John,
no word yet on the Mullard. Listened to the Ei12AX7 last night again - gave it a 2nd chance, so to say. A little better. I think that I haven't heard what this tube is capable of until I think that it reaches 75 hrs. That's too many more hours more to go!
So, I'm going to try the Mullard either tonight or tomorrow night (depending on the domestic situation).

Hi All,
Heard the Mullard 12AX7 tube last night & wanted to share the experience:-
The Mullard was placed in position V8 & V9 (like the other 2 12AX7 tubes provided), which is the line-stage section for those familiar with this preamp.
* high freq extension is very good. Much like the Tele 12AX7. For the 1 1/2 hrs I listened last night with a limited set of CDs, I could not discern any glaring diff between the above 2 cited tubes.
* mid-range - glorious! I think that this is what Jafox had been "warning" me of. Esp. with vocals. The voices soar & there's a certain sweetness to the voice (bloom?). Slightly more than the Tele 12AX7. Listening to trios/bigband with vocals was a pleasure.
* mid-bass - weak in my system.
* bass - weak in my system.
These 2 ranges of the freq spectrum, the Mullard came up short vs. the Tele 12AX7, the 12AX7EH (that I've been using for 3+ years) & even the Ei12AX7. The Ei12AX7 lost big-time to the Mullard in the midrange but it did have very nice bass. I realize that the Ei12AX7 is not broken in.....
Anyway, the Mullard does have mid-bass & bass but it's light-weight in my system & the sound spectrum seemed tipped up. I know & I've heard that my system is capable of more. If I hadn't heard any other tube besides it, I would not have realized this. Unfortunately, I have!!
Since I like a balanced sound nearer to neutral than not, the Mullard would be a 2nd or 3rd choice, I'm afraid.
Anyway, that's the long & short of it. Sorry if I have stepped on your toes. FWIW. IMHO. YMMV.

Hey good report here. I think the results are another example as to the importance to try different tubes on our own components in our own system. And this is what makes it possible to tune a system to our own liking.

Last week, during a power cable audition with two local audiophiles, near the end of our listening session, we swapped the Tele 12ax7's in the Callisto to the Mullard. There was clearly more resolution on the top, not so much extension, but simply more presence of percussion brushes, with the Mullard than the Tele. I felt this was as big if not more significant than the huge cost increase of a few power cords we had swapped. I don't think any of us noticed a reduction in the mid bass or bass with the Mullard. So in the context of the Aesthetix Callisto, we all much prefered the Mullard but for now anyway, the Tele is the tube to beat in the Io. I hope to soon try Mullard vs. Tele in various positions in the Io as there are 12 12ax7 tubes in this beast and 6 more in the PS.

Bombay, when you get a chance please send back the Mullards as I want to loan this pair to one of the local guys. And then I am eager to play with the Io. You can play with the Tele and EI for as long as you like.

John