I've acquired a Telefunken ECC 82 tube that I'm very satisfied with. It's the most quiet tube I've tried to date. There are three times 2 2 2 numbers in the bottom of it (in a pyramid / triangle shape, i.e. one 2 on top and the other 2's below). Packaging just says Telefunken on the sides and ECC 82 on the top. Anyone that can tell me more about this specific tube / batch? I'm asking out of curiosity and because I'd like to buy more if the can be sourced. Thanks in advance, Kasper The first image shows the 2-2-2 numbers the clearest -> Top of the tube shows 515 on two sides. Says: Telefunken EC82 - Made in Germany
that pyramid etched on bottom glass is often called “diamond bottom” which is a clear indication of genuine Telefunken tube made in West Germany. if you can provide numbers written vertically on side of the tube manufacturing date can be revealed. it is most probably made in Berlin factory.
You're right, I'm sorry. Everything looks right when I'm logged, but the images are broken when I check the thread from another browser. I've uploaded the photos here instead: Telefunken ECC82 - NOS (New Old Stock) mærket 2-2-2 - Made in Germany - Blog
Thank you for the reply I think the serial number on the side of the tube reads: 5 9 205626 With the par marked in bold is readable. I'm not sure the two first numbers (5 and 9) are correct.
In addition - is this specific version typical of the general level of noise in NOS Telefunken tubes? and - what do the three 2's mean? I can see others have a 6 and 2 2's.
it is a regular one but all Telefunken tubes are famous with their low noise and long life characteristics. 2 or other number etched on the glass in diamond doesn't mean anything.