Genuine Telefunken?

To be clear to the novice , the Diamond is located in the middle of the Pins and part of the glass itself .

After reading as much as possible on the net about " NOS " tubes, have narrowed it down to Telefunken 12AX7 and 12AU7 for my Jadis DPL preamp

This could be a disappointment if you do not audition other tubes. There's no way to know how the Tele might work with the Jadis unless you listen to its performance to others.

The Tele 12ax7 was outstanding in the Aesthetix Io phono stage but it just never cut it for me in the CAT and Manley products I owned; the result was rather dull. The Sylvania 5751 was a big improvement to the Tele 12ax7 in the CAT product. As for the Tele 12au7, it compared poorly to those from Mullard in the CAT. But there are so many other 12au7 tube types out there that to focus solely on the Tele could limit your preamp's performance.

I enjoyed the Tele 6DJ8/6922 in the Aesthetix and CAT products, but after playing with Amperex tubes the last year or so, particularly the 6922 and 12au7 families, I am less and less impressed with the Tele tubes. They are good but way overrated after hearing the Amperex.

Sirspeedy - YES. The Amperex 6922 PQ PW's. This is my reference 6922 tube. It's a killer in the CAT and excellent in the Aria preamp. But it was soon displaced in the Aria by its cousin, the Amperex 7062 PQ PW. The 7062 is a 12v based tube so it is not directly replaceable from the 6922 ...... except in the Aria with a flip of an internal switch. 8-) The 6922 PW is very smooth with great dimensionality. But the 7062 PW beats the 6922 PW at its own game and quite handily...and with greater dynamic contrasts. The Amperex tubes are special.

It is always possible to purchase an authentic Telefunken tube that is unfortunately past its prime and/or microphonic so making sure the tube has the diamond on the bottom guarantees you nothing sonically. Do yourself a real favor and deal with a quality tube dealer. Call Andy at Vintage Tube Services: 616-454-3467

I can vouch for the Jadis/Telefunken match, in my JPL and JP80 the Telefunkens sounded far more lush than the Mullards I tried, so go figure. It's good to try other types (Amperex Bugle Boy 6DJ8s sounded great in my JP80's phono stage, better than the Teles in that position, so I imagine their 12AX7s would sound good), but I have always wound up with the Teles in my Jadis equipment. And Larryi is right, the ECC803S are the best of the Teles that I have used, but they are outrageously priced these days. Mine have been going strong for years, so the high cost has been well-amortized. Do watch out for fakes; if you buy from a reputable seller you can be confident you'll get the real thing.

The info on the genuine Tele's having the diamond molded in to the bottom glass, and their excellent sound qualities is all correct. I've not seen this counterfeited as yet. Only pursue a British tube(ie: Mullard, Brimar) if you have a taste for a warmer/tubier presentation. The better Tele's and Siemens are about as transparent/smooth/detailed/dynamic as tubes get, unless you go with a pair of these: (http://www.euroaudioteam.com/ecc803s.php) and take the risk out of the game altogether. BTW: The ECC803S is a 10,000hr tube, which(combined with it's exemplary sonics) makes it somewhat of a bargain.