Want to upgrade 12ax7's on Jadis OR

First let me say thanks to all the folks in here who have shared their advice and passion of hi-fi with me. Audiogon has become a site that I visit every day... so much great information about the stuff I love most... THANK YOU !
OK . . I have a pair of electro harmonix 12ax7's in my JOR right now, and the system sounds ridiculously excellent to me. I am trying to see if there is a tube that is pretty well undisputed as a marked improvement over my tubes.
I am learning as I go, but I have been reading of Telefunken, Mullards, Amperex, Brimar and some of the other well respected brands, but not sure which would be a better choice over my stock 12ax7's. I'd like to hopefully just make one purchase and be happy with it.
Any recommendations ?
Thanks - Matt
My all time favorite 12AX7 is the Amperex long plate D-getter's. For details regarding its sonics, along with the other great tubes you mention, take a look at my review of the Accustic Arts Tube Hybrid DAC, were I describe why I ended up with these tubes as my reference.
12ax7 Amperex Bugle Boy - Tungsram ( hungary ) 12ax7 and for 5751 RCA 3 mica Black plate ( warm ) GE 5751 black plate ( neutral ) ...All great tubes more of a system synergy issue..

New pruduction 12ax7 I like the Ei Cryo 12ax7 from ( tubedepot.com )
I found Brent Jessee, a tube dealer close to Chicago in Hoffman Estates who has a great selection on tubes and gives a 30 day full trade in on his sales. I have chosen a matched pair of 12AX7 Telefunken ribbed plate, diamond mark,for $175. They sound very good, even at a very low volume.

This is my first tube swap and I can hear a difference in the cleaness of the highs and the overall improvement in the soundstage.

He suggested possibly trying out some NOS KT88's. I just bought some new Russian Genelex Gold Lions and he said that they are OK, but not in the same league as some of the older KT88 from the 60's. So I may be selling my Genelex on Audiogon pretty soon.

This seems like a way to slowly upgrade to some of the more expensive Amperex tubes that have been suggested.
does penta labs make 12ax7`s and if yes are they any good
I have not heard them, but I Googled and found then on Doug's Tubes. They seem fairly inexpensive and the are reported to be used on high end recording gear.

Hope this helps.

Went through several different 12AX7's in my phono stage (Hagerman Trumpet) recently that were loaned by a friend who has a stock. I liked the Tung Sol 12AX7's the best. Detailed, open with no grunge but still musical.

I also heard RCA black plate 5751's (2 mica version) and was not overly impressed. They definitely had lower gain but were fairly average sounding in my Trumpet. May be better elsewhere.

There was a Baldwin organ pull 12AX7 (not sure who made this and I've never seen it before) that had a lot of punch with an open and very clear top end. However, the mid bass was a little plumy and slow. But not a bad tube if you need a little warmth.

Well... I just bit the big bad bullet and bought a pair of Mazda Silver Anode SELECTED 1962-1963 date coded vintage 12AX7S / ECC83, Ultra-low noise premium 12AX7, TRIPLE-MICA, standard pins.

The decription from Brent Jessee's web site says:

New Old Stock in original boxes. Can this rare, amazing tube be improved upon? YES! This is a very low noise, seldom seen special quality 12AX7, with bright silver anode plates. Like the standard version below but with triple mica support, and factory selection ("S" suffix) for superior performance, internal matching, and low noise. These have the ultra wide bandwidth of the Telefunken ECC803S, with nearly identical sonics, which are refined, smooth and accurate. These have slightly higher gain than most 12AX7 tubes, which gives this tube better punch and clarity. AWESOME in phono stages and mic pres. Compare the price to the more expensive and equally rare Telefunken ECC803S! These tubes are currently soaring in value as stocks of them vanish. 1962-1963 French Mazda manufacture, these are NOT the later Sovtek or Svetlana silver anode tubes which are not nearly as good. Virtually unavailable in the USA, these came direct from an old electronics shop in the Normandy Coast area of France. Carefully matched, a very rare chance to grab a matched pair of these superb vintage tubes. SINGLE TUBES, WHEN AVAILABLE, ARE $200.00 EACH.

So.... I should have them Friday and hope to be able to enjoy both them and a new Teac VRDS-10 CD player that I should be receiving tomorrow.

I will be selling a few items pretty soon because my wife is starting to give me the evil eye. And she doesn't know that I starting researching another quad of KT88's yet either.

P.S. - I am starting to really believe that I am addicted to HiFi.... coke would probably be a lot less expensive, but I doubt if it would be as enjoyable.

Happy listening !