Make of vintage 12AX7

[tubeboob]

Over the weekend I stumbled upon a NOS 12AX7 marked GE but made in England.

Does anyone know if this is a Mullard, or what else it may be?

Thanks

 

[audiodon]

Probably would be good to have a picture, but a lot of vendors made tubes labeled for others. Does it flash at the base when you put it in a circuit and turn it on? If yes, Mullard. The flash is harmless, by the way.

 

[Tom Bavis]

Look for etched codes near the base - they tell all. First line is tube number (but you know that!), second is plant and date. 'B" is Mullard Blackburn.

 

[tubeboob]

More info.

About the middle of the tube are the numbers:

FW
188-5

And near the base is:

163
B6H1

And on the bottom between the pins, what looks like a reverse "F"

Also, it says 12AX7 GT. BRITAIN near the top.

Thanks in advance.

Cheers

 

[jon_s]

I have a number of GE 6922s which are Mullards. Great tubes, and I got like 8 of 'em NIB for $60 on eBay.

 

[kvflyer]

If it has lines in the glass, or slight ribs on the top, it is most likely Mullard. Of course, the B6H1 is most likely a Mullard factory and build date...

 

[tubeboob]

It has lines in the glass.

It has slight ribs on the top.

And it lit brightly on switch on and then diminished.

I guess it is most likely is a Mullard.

Thanks all for your input.

Just love this vintage tube stuff!!

Cheers

 

[GordonW]

I have one exactly like that one. BrassTeacher indeed did verify it was a Mullard.

Regards,
Gordon.

 

[FalconEddy]

About the middle of the tube are the numbers:

FW
188-5

And near the base is:

163
B6H1

And on the bottom between the pins, what looks like a reverse "F"

Also, it says 12AX7 GT. BRITAIN near the top.

Thanks in advance.

Cheers

Mullard.

It's an I6 (12AX7) 3rd series production.

Blackburn facility produced

Most Likely the first week of August 1976. This is because the GE information shows it was labeled at the Owensburg Kentucky plant in March of 1964. Obviously one is right, and the other is wrong.

Mullard and third party relabelers really made a mess of things when they printed conflicting date code on tubes (which happened quite often).

The ECC83/12AX7 tube made by Mullard was one of the tubes that didn't change the production series codes between 1964 and at least 1976. They were marked I63 which was a bit confusing. However, tubes that were Mullard labeled had two different shield designs. The 1964 12AX7's had the old style shield, and the 1974 12AX7's had the new style shield. That how the year could generally be identified.

However, this did nothing to identify the actual year of production when third party relabelers got involved.

So, despite the conflicting dates. . . yes, they're Mullards.

. . Falcon

 

[paulram]

Darn ....you guys are so knowledgeable...Im impressed !!!!!