Tube Question....trying to ID these 12ax7's

[st3v3ss]

I was given these tubes recently and am not sure who made them or from what year they may be as all the writing has worn off. Any help would be appreciated.

[what_wires]

They could be from anywhere. You should look past the "snob factor", plug them in and give them a listen, you may like what you hear.

[Phil_S]

Seriously, put the in the freezer for a while. Sometimes this will bring up an impression of what used to be printed on the tube.

[betawi-bule]

I have some RSD (East Germany) ECC83s which are identical to what you have there. From what I've scraped off the i-net, these particular RSDs were re-labled Ei - reportedly a Yugoslavian copy of the Telefunken smooth plate. They look very similar to the real smooth plates but the holes in the sides of the plates are spaced closer together on the Ei/RSDs.

Regardless they sound great in V1 of an 18watt ... Try em out!

[blaren]

Ei

[st3v3ss]

Thanks for the replies. I did put one in V1 and is does sound pretty good.