I have acquired some used ribbed plate telefunken 12ax7s recently and
noticed there were differences from what I could see on the web:
(1)same features - Telefunken logo, clean diamond at base with numbers,
"Made in Western-Germany", "ECC83/12AX7", and the prints are water
soluble (easy to wipe off).
(2)different features - The "Telefunken" logo is small, probably ony
3/4 of the others. The "ECC83/12AX7" label is above the logo, and there
is no vertically transposed date code printing on the other side at
all, instead there are just 2 small characters saying "w1" (or "wl").
They sound great on my dynaco preamp, a little bit richer in bass
compared with the stock dynaco Telefunken oems (subjective of course).
Would appreciate info from anyone knows the history/story of these
"small" logo teles. Are these old productions?
TIA.