Valve recognition

[Saxman]

Hi All
To you knowledgeable valve guys I have what I think are two ecc83 but not sure what they are. The printing has gone from the glass except for two numbers which is a 12 and 340 underneath it.
The tips of the valve are painted red and green.
The getter is a O getter with one support.
Two mica spacers with 17 mm plates which are grey ribbed with two slots and one hole on each side of the plates.
The only other identification marks are one valve has a T embossed on the base the other a J.
Any ideas anyone
Thanks
Alan

[Fran]

9 pin base?

The only other thing you can do is check resistance between pins - heaters should show lowish resistance which might put you in the family at least...

[Saxman]

Fran
Thanks what would be the difference between a ecc83 and ecc82 in respect of higher or lower voltage.
I could put them in the pre amp and try them by listening to the volume levels but reluctant to do that in case I damage something.
Cheers
Alan

[Saxman]

Hi Fran
I meant resistance in ohms not voltage to early
Cheers
Alan

[Fran]

The resistance will be the same across the heaters whether its 12ax7 or 12at/au/xx7. But at least you'd know that the pin out is pretty sure to be correct. I've heard people advise before to put one in on one channel and if the volume is lower then you know its a 12at7. No matter how you do it that feels risky though.

I also heard people saying if you put it in the freezer for a little while, then take it out, as it fogs up it often will show the lettering, or where the lettering has been.....

[Saxman]

Thanks Fran will try the freezer option

[Saxman]

Ah well that never worked will send details to valve distributor in UK see if I get any response

[Diapason]

Gotta say I'm intrigued here. Don't think I'd go sticking them into anything though!

[Saxman]

Not going to somebody somewhere must know what they are though

[Diapason]

You could try emailing Brent Jesse?