2 – Telefunken ECC83 12AX7 Ribbed Plate Tested Strong on my Eico 667 Also used in my phono preamp.
TWO Telefunken ECC83 12AX7 Tubes / Ribbed 17mm Long Plates / Diamond Logo Bases
17mm long grey plates. Tubes test at 1500, 1500 and 1400, 1500 where 1040 micromhos is pass/fail grade. NO SHORTS / ZERO GAS. Diamond logos on bottom base. One marked West Germany other Germany. % Test results in percent %.