National 12AX8's, who made 'em?

[Regis]

I have three National Brand old stock 12AX7's, my understanding is that they didn't make tubes but rebranded other manufacturers tubes.

Is there any way the original manufacturer can be identified? They say Yugoslavia so maybe Telefunken? Are they worth anything?

I've attached links to pictures.

tube01 (http://bellsouthpwp.net/d/o/doctorx/tube01.jpg)
tube02 (http://bellsouthpwp.net/d/o/doctorx/tube02.jpg)
tube03 (http://bellsouthpwp.net/d/o/doctorx/tube03.jpg)
tube04 (http://bellsouthpwp.net/d/o/doctorx/tube04.jpg)

Thanks,

Regis

[Rob Mercure]

Hey Regis,

EI made many tubes in Yugoslovia as did "Teslovak" (sp?). "Real" Telefunken tubes were made in West Germany and can be identified by a raised "diamond" figure on the base between the pins - but there were a number of German, and other nations, made tubes that were marketed by Telefunken once they stopped their own tube production - Seimens, RTF, and Tungsram (Hungary) - for example.

The real "tube nuts" (said affectionately) hang out on the "Audio Asylum" web pages and can probably identify most anything - just don't ask their opinions on anything unless you're prepared to get it <grin>!

Rob

[dai h.]

they say Yugoslavia and it's true. Those are made by Ei.

[Bruce / Mission Amps]

I agree, the insides look like my old stock EI ECC83 tubes.

[Regis]

Thanks, Guys.

I am ramping up to sell my Quad Reverb and was wondering if these would sweeten the sale.

[Le Basseur]

Hi Regis,
+1 about your tubes being EIs!:)


EI made many tubes in Yugoslovia as did "Teslovak" (sp?).
Rob,it's a little confusion here:EI factory IS in Yugoslavia,more precisely in the small Serbian city of Kragujevac (English read:"Kraguievatz" with the accent on "gu").As you already might know,they have some older ('78-'80) Philips tools and they produced,aside of the genuine-branded EI tubes,a lot of others,mostly on order (I recall Conrad-Johnson).
"Teslovak" had absolutely nothing to do with the EI production,AFAIK.I never saw a EI tube rebranded "Teslovak",maybe for the simple reason that "Teslovak" is a derived brand name of the pre-90' Tesla.The Slovakian branch used to rebrand their tube "Teslovak" for a short period of time.Lately,after the "Velvet Revolution" in 1990,the Slovak Tesla became what we know today as JJ Tesla while the Czech factories were mostly sold (and lost for the world of tubes) with the notable exceptions of what tube gurus like Alessa Vaic and Riccardo Kron manage to rescue.
(...) there were a number of German, and other nations, made tubes that were marketed by Telefunken once they stopped their own tube production - Seimens, RTF, and Tungsram (Hungary) - for example.

Again,AFAIK and what I had on hand...two Western German brands (Siemens and Valvo) used to rebrand as "Telefunken" some of their tubes during the "Golden Era" but these tubes had no "diamond base stamp".
On the other hand,it's a little foggy what happened with East-German tube factories,RFT being the most noticeable of them.It's obvious that they used to rebrand big time but,also,there are alot of Russian tubes rebranded as Western (as the East-Germans had them in big quantities).What comes in mind is the infamous ECC189 and PCC189 as well as a bunch of poor-quality 6L6s.
Third,the Hungarian Tungsram...hmmm,the same forgeries here with tubes produced either in Hungary or in USSR,but rarely bearing the name "Telefunken".Most often,"Ultron".
Also,there was a Polish factory (PolAm) but I saw only originals from them,no rebrands.
HTH!
Regards,