Some EL34's are listed with cathode leak. This means there is some resistance between the cathode and the heater, normally this should be infinte. Many people are selling tubes with cathode leak and do not mention it, or cannot measure it. I can measure it and do mention it. It is not a problem in any normal amp, because the leak is parallel to the cathode resistor, which is always much smaller than the leak. Especially amplifiers with negative grid supply (like Dynakit, Heath, and many more) work great with these tubes. Personally I use them in my Dynakit MK IV amplifiers, they sound very great. The leak gives you same quality in sound, but a nice reduction in price!

Original stock European made EL34 (Philips and Mullard, for Telefunken please scroll down)
These EL34's (typical picture) are in white box, the tubes called NOS are in original cases. They all have a hole in the centerpin. Original make can be seen in the datecodes. The second part of the datecode starting with an X or L are made by Philips, starting with a B are made by Mullard (Blackburn works, UK). For example: the Xf2/B2I2 is made by Mullard, the Xf3/X9G (or L) by Philips. For more information about these factory and production codes, please take a look at this great pages.

Branded as	Getter	Base	Datecode	Description	mA	State	Price(Euro)
Philips Miniwatt	Double D	Brown	Xf1/X7F	Welded plates	88	NEW	82.00
Philips	Double D	Brown	Xf4/L1B	Welded plates, small cathode leak (3MOhm)	80	USED	24.00
Adzam	Double O	Black	Xf2/B3I4	Welded plates, in original case	98	NOS	72.00
Philips Miniwatt	Double O	Black	Xf2/B3E2 Xf2/B6C1	Welded plates. Bad getter flash, but ok tube on one, other perfect. Different Miniwatt logo. One in original case	82 84	NEW/NOS	160.00 (pair)
Pope	Double O	Black	Xf2/B6B4	Welded plates	94	NEW	62.00
6CA7/EL34	Single O	Black	Both Xf?/B9E3	Welded plates, Labelled "6CA7/EL34, made in Gt. Britain"	Both 98	NEW	140.00 (pair)
Philips	Single O	Black	No codes	Matched pair, small glass, later production EL34	82 84	NEW	62.00 (pair)

EL34 made by Telefunken
All these EL34 are in white box unless noted otherwise.

EL34 made by other manufacturers

Branded as	Getter	Base	Datecode	Description	mA	State	Price(Euro)
Siemens	Single O	Black	bD3/?9K picture	Three holes in plate, welded plates, very typical Siemens dimple top version, very good sounding and quality tubes, Joegoslavian made	80	NOS	45.00
Siemens	Single O	Black	??? picture (alike)	Two holes in plate, made by RFT, stapled plates, matched pair	76 76	NOS	62.00 (pair)
Siemens	Single O	Black	N89	Two holes in plate, stapled plates, in original Siemens case	78	NOS	22.00
Tesla	double O	Brown	??? picture	Two holes in plate, welded plates, NOS Tesla, very good sound and quality. 2 single and 1 pair left	misc	NOS	27.50 62.00 (pair)
Tronal	Single O	Black	??? picture (alike)	Two holes in plate, made by RFT, stapled plates, matched pair. Different boxes, but same tubes	96, 100	NOS	64.00 (pair)
Tronal	Single O	Black	??? picture (alike)	Two holes in plate, made by RFT, stapled plates, matched pair. No label on tubes	86, 88	NOS	64.00 (pair)
Radiotron	Single O	Black	???	Made by RFT. Two holes in plate, stapled plates	78	NOS	24.00
RFT	Single O	Black	TGL 3649 picture	Two holes in plate, stapled plates	86	NEW	22.00
RFT	Single O	Black	???	Two holes in plate, stapled plates, testing good	64 72	1 pair	29.00 (pair)
RFT	Single O	Black	???	Two holes in plate, stapled plates, testing good	64 72	1 pair	29.00 (pair)
RFT	Disk	Black	930203	Testing good, two holes in plate, stapled plates	66	USED	7.00

EL34 New production

Steel based EL34 made by Mullard and Telefunken
The EL34's below (typical picture) are in white box. All tubes below are very probably made by Mullard. They have Mullard datecodes and a hole in the centerpin.

Branded as	Getter	Base	Datecode	Description	mA	State	Price(Euro)
JJ Electronic E34L	Single O	Black	2004 Picture (alike)	Two holes in plate, welded plates, look very nice and strong build. New production tubes. Matched pairs and quads	80-100	4 pair 8 quads	29.00 (pair) 59.00(quad)
EL34-EH	Disk	Black	2002	Two holes in plate. Matched pairs and quads	80-100	4 pair 4 quads	20.00 (pair) 44.00(quad)
6CA7	Disk	Black	2002	Fat bottle, great tube. Matched pairs and quads	80-100	2 pair 3 quads	30.00 (pair) 64.00(quad)
Valve Art	Single O	Brown	9-1-1999	Two holes in plate, welded plates, look very nice and strong build. New production tubes	110	1 quad	59.00(quad)
Svetlana	Single O	Brown	0212	Stapled and welded plates, made in Russia	88	1 single	8.00
???	Double Disk	Black	No code	Very heavy and strong build, looks like some new production	84	1 single	12.00

Branded as	Getter	Base	Datecode	Description	mA	State	Price (Euro)