[mordy]

Thanks for the info mordy!, along with the black glass TFK's was a grey glass version, a ST Valvo and a unbranded straight glass, will check those bases for dates.

If you find the two letter code by the pins on the straight glass it is a TFK. Here is a link to the codes with a useful chart:
https://tctubes.com/telefunken-date-codes.aspx

 

[connieflyer]

I see a lot of you folks are still using the 6SN7 variety of tubes. Here is a link for those of you that have not seen it. Very interesting breakdown of the 6SN7 family. A must read. https://www.head-fi.org/threads/the-reference-6sn7-thread.117677/

 

[Scutey]

If you find the two letter code by the pins on the straight glass it is a TFK. Here is a link to the codes with a useful chart:
https://tctubes.com/telefunken-date-codes.aspx

That's great, cheers!, I'll keep the link and check them out when they arrive .

 

[hypnos1]

I finally received the EL38 adapters from China. I just fired up Euforia with 2xKen Rad 6SN7GT as drivers and EL38 as power tubes.
The sound is pretty amazing, even with almost no warm up of the amp. I guess the word that comes to mind are "depth" and "speed": bass notes are so precise!

However I have noticed that at relatively high volume the bass starts to distort on my HD800. It is not that it is overwhelming, but real distortion.
I have tried with other phones that I have around and the effect is there in all of them.

Have you guys noticed a similar problem?

EDIT: mine only have 7 pins.... and a "hole" where the 8th pin usually is in other tubes....

Hi Tunkejazz.

There shouldn't really be any such problem, but as @connieflyer said, perhaps it will subside after a bit more burn-in....do hope so. If not, it definitely is a bad tube and you're perfectly entitled to a refund...no question lol!!

As for the missing pin, that's quite normal, given pin #6 isn't used.

 

[hypnos1]

Hi T.J. I had similar problem today pairing my Valvo EL11's with my newly obtained EL 39's. At higher volume which on occasion I do use I experienced bass distortion. These Valvo's work perfectly with both Elise and Euforia with 38's as powers The problem was cured when I exchanged the Valvo tubes with EL32's and then Telefunken EL 11's.
I found with other tubes combinations that the Euforia can be rather more fussy than the Elise. I have in the past used both Ken rad and Sylvania 6SN7's as drivers in both amps with 38's as powers with no distortion throughout the volume range. I think its a case of trying various driver tubes until you come up with a perfect combination.

Hi bt...glad the adapters arrived promptly and safely, and hope that you find they continue to improve with more burn-in of both them and the tubes.

Strange about that bass distortion when driven by the Valvos...I myself have never had any such issues, either from my mesh-plated versions or 'standard' ones. Might be worth giving them longer time partnering the 39s and seeing how it goes...if you so wish lol! . But there are indeed plenty of other good tubes that I'm sure will excel driving the EL39s. Sometimes, a great deal also depends on the partnering gear...especially the DAC's output. And was it the same with all headphones? Looking forward to how things progress...CHEERS!...CJ

 

[DecentLevi]

Johnny have you gotten to try the Senn. HD 579's on your Euforia yet?

 

[DecentLevi]

From my experience after what must be the largest ever tube rolling on the Euforia, that distortion on louder levels is usually one of the amps' signs that it doesn't like the tube combination, so I second that another class of driver/power should cure the problem. Though it is peculiar to receive distortion on the EL38 power + 6SN7 combo so this one could be down to tube condition on either side. Also I've noticed that usually distortion / volume break up on high volume is an indicator that there are also trace amounts of distortion on normal levels as well.

 

[Johnnysound]

Not yet, DL....picking the phones tomorrow from my courier. BTW, since both you and @mordy liked them so much, got a pair of NOS Ken-Rad 6N7/VT96, 44’ vintage for about $ 22, shipping included (!). I now suspect that early 6N7xx types (as the 7N7s) will sound great in Euforia, specially paired with the EL38s...and EL39s, most probably.

Been watching the 6N7G (ST type, nice looking) and the 6N7S (straight glass), various brands, and quite a few of them do have round black plates, (some dark glass), I would say exactly the same plates as the famous (and very expensive) “Tung Sol BGRP”...but at less than one tenth the price !!

Any experiences ?

 

[DecentLevi]

Cool Johnny on the 7N7 acquisition, but be advised these also need adapters! (XuLing's on eBay are quite decent). Also do note these are perhaps the most picky on synergy of any tubes I have ever tried. So my advice if you get the 7N7's is to try them with every possible combination of powers and see what works best. Many combos with these have distortion and some are super standouts, so test, test, test.

On my 8x tube config. on the Euforia I must have already tried around 300 combinations and have about 5 pages of combinations just for the external adapter combos; I've almost given up trying every mathematically possible combination having already so many stellar favorites at this point, especially since I'm starting to gravitate towards other amps having tasted so much guilty-pleasure at the meet last weekend, LoL! I often don't even bother tube rolling with having to go through the list and change so many at a time with the way my amp is set up, but at least it's taken me to great new sonic heights.

 

[barontan2418]

Hi bt...glad the adapters arrived promptly and safely, and hope that you find they continue to improve with more burn-in of both them and the tubes.

Strange about that bass distortion when driven by the Valvos...I myself have never had any such issues, either from my mesh-plated versions or 'standard' ones. Might be worth giving them longer time partnering the 39s and seeing how it goes...if you so wish lol! . But there are indeed plenty of other good tubes that I'm sure will excel driving the EL39s. Sometimes, a great deal also depends on the partnering gear...especially the DAC's output. And was it the same with all headphones? Looking forward to how things progress...CHEERS!...CJ

Hi H1.
Adapters are perfect, many thanks. After a bit of driver tube rolling I have finally settled on a Valvo and Telefunken EL11 + EL39's combination which is certainly an improvement on all previous tube types/combinations I've used . Playing Aaron Copland's Rodeo at the moment (one of my favourite test CD's) and it has never sounded better, clarity, definition and instrument placement are top notch. So thanks again for introducing us to the EL39.

 

[Tunkejazz]

Hi Tunkejazz.

There shouldn't really be any such problem, but as @connieflyer said, perhaps it will subside after a bit more burn-in....do hope so. If not, it definitely is a bad tube and you're perfectly entitled to a refund...no question lol!!

As for the missing pin, that's quite normal, given pin #6 isn't used.

Some news on the EL38 tube problem: I gave them some extra amp hours and the distortion is gone. It seems that the tubes needed to "settle".
I find this effect very strange, never in my life had a similar behaviour with any 6SN7, 6080 or 6AS7G tube.

Perhaps...the EL38 were brand new/ never used?

 

[barontan2418]

Diverging from the subject slightly, what's your oldest tube in use on Euforia/Elise. Mine I believe is Telefunken EL11 D.R.P
Which having looked it up on Google stands for:
WWII ORIGINAL GERMAN WWII original German radio tube Telefunken. Bears the DRP mark (Deutsches Reich Patent)

Tubes lettering code is hd which puts it at Oct 1938. Amazing that a tube 14 years older than me still rocks, my wife would tell you I stopped rocking long ago.

 

[hypnos1]

Some news on the EL38 tube problem: I gave them some extra amp hours and the distortion is gone. It seems that the tubes needed to "settle".
I find this effect very strange, never in my life had a similar behaviour with any 6SN7, 6080 or 6AS7G tube.

Perhaps...the EL38 were brand new/ never used?

That's good news Tunkejazz...this sort of thing does happen from time to time alas! And yes, it may well be because new. Hope you stay trouble-free from now on...

 

[hypnos1]

Hi H1.
Adapters are perfect, many thanks. After a bit of driver tube rolling I have finally settled on a Valvo and Telefunken EL11 + EL39's combination which is certainly an improvement on all previous tube types/combinations I've used . Playing Aaron Copland's Rodeo at the moment (one of my favourite test CD's) and it has never sounded better, clarity, definition and instrument placement are top notch. So thanks again for introducing us to the EL39.

Glad you've found a good combo bt...and that you're enjoying the EL39s. Things can only get even better lol ...CJ

ps. Had another mini shock the other day...plugged in my HD 650s (which I relegated to expendable testing cans when I got my Beyer T1s!) and what can I say? With the EL39s in place, I couldn't believe how good they now sound. Nowhere near the Empys, of course, and lacking the T1's also wonderful soundstage and airiness, but much better than I've ever heard them before nonetheless. These tubes certainly do seem to have been sprinkled with more than their fair share of Fairy Dust lol!!......

 

[mordy]

Diverging from the subject slightly, what's your oldest tube in use on Euforia/Elise. Mine I believe is Telefunken EL11 D.R.P
Which having looked it up on Google stands for:
WWII ORIGINAL GERMAN WWII original German radio tube Telefunken. Bears the DRP mark (Deutsches Reich Patent)

Tubes lettering code is hd which puts it at Oct 1938. Amazing that a tube 14 years older than me still rocks, my wife would tell you I stopped rocking long ago.

Hi barontan2418,
The oldest tubes I have are from the 1940's WW2 era. As you mentioned, it is amazing that these 70-75 year old tubes are still working perfectly - wish I could say that about myself; I am in that age bracket as well.....