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Is there a rhymn or reason to tube numbers. I know theres european numbers and what we use here in the 'colonies' but was there ever a plan or were these just partnumbers someone made up at the factories? Just was always curious about that... I just wondered if certain 'types' of tubes I.E. octal rectifiers always started with say 5 ( I know GZ34 but was that because they ran out of good numbers?). Maybe a stupid question, but consider the source. Please don't subtract stars for this...

Regards,

Dyna

Most of the time when you see a 5 or 6 in a tube part number, you know that it's filiment is 5 volts or 6.3 volts. Likewise, a 12AX7 tube is set up to use 12.6 Volts which was very convenience for car radios back in the day. When we use a 12AX7 we wire it in parallel so the filiment voltage is back to 6.3 Volts. Now how the English named there tubes in a good question for a "limey" so how about it Loverocker? What's the deal?

str82hvn

Edit... Fingers ingaged keyboard faster than brain...

Parallel not series...duh

http://www.duncanamps.com/technical/tubenumber.html

I never knew there was a "nonode" tube. Wonder what one of those sounds like in an amp?

str82hvn wrote:When we use a 12AX7 we wire it in series so the filiment voltage is back to 6.3 Volts.

Rethink.

Awesome! Thanks much, very much appreciated.

Regards,

Dyna

As you will see the European system is much easier to interpret.

bender wrote:I never knew there was a "nonode" tube. Wonder what one of those sounds like in an amp?

A "nonode"? That must be a glow discharge like an 0A2, 0B2, etc. They're a regulator tube for power supplies, I don't like 'em... they get rid of my luvverly "sag"!

zaphod_phil wrote:As you will see the European system is much easier to interpret.

Ah, a spokesman for the entirely inscrutable European system! I guess all ya got to know is that ELs are power amp tubes, ECCs are preamp tubes, EZs and GZs are rectifiers. I guess it's simple...

With the North American system you can indeed tell at a glance what the tube is likely to be IF you're semi-familiar with the system. Take something like a 6L6, then look at a 25L6, 35L6 or a 50L6. Same tube, different filament voltage. So the first number is filament voltage. Guess that means "6" series tubes should really be 6.3 series tubes!

Next, the letters. That's the category of the tube and Phil's right, there's only a glimmer of sense to it.

The last number is the number of elements in the tube which probably doesn't matter much as the system doesn't differentiate between grids, plates, cathodes, etc. There's five elements in a 6BQ5, six elements in a 6L6, seven elements in a 12AX7.

European valve numbers are a bit difficult to interpret if you are unused to them, but here goes(translated from my local parts supplier catalog):

First letter corresponds to the filament voltage/current:
A = 4V
E = 6,3V
D = 1,4V battery
G = 5V
H = 150mA series
K = 2V battery
P = 300mA series
U = 100mA series
V = 50mA series
Q means that the valve is a tetrode for transmitter poweramps

Second letter tells what kind of valve it is:
A = diode
B = double diode
C = triode
F = low power pentode
H = heptode
L = high power pentode
M = "magic eye"
Y = rectifier

A third letter tells that the valve has dual functions, example: ECC83, 6,3V with two triodes.

Sometimes numbers and letters are displaced to tell that it is a certain type of valve, E83CC for example is a longlife variant of ECC83.

It also exists valves which doesn't correspond to this system, KT66 for example(KT stands for Kinkless Tetrode).



/Bengt

Groundpath wrote:

str82hvn wrote:When we use a 12AX7 we wire it in series so the filiment voltage is back to 6.3 Volts.

Rethink.

Indeed, it's parallel wiring of the two filaments that allows usage with 6.3 volt supplies as opposed to using the two elements in series for 12 volt supplies.

Dynaflow_Donnie wrote:I just wondered if certain 'types' of tubes I.E. octal rectifiers always started with say 5 ( I know GZ34 but was that because they ran out of good numbers?).
Regards,
Dyna

Dyna,
The American equivalent of a GZ34 is a 5AR4.