Tubes Asylum

Posted by amandarae (A) on October 26, 2023 at 09:57:28

In Reply to: RE: tube no longer works after cleaning pins??? posted by boodles on October 25, 2023 at 06:05:35

I have been using a 01A/201/301 preamp for years now.
My experienced when having pin contact issues was always having poor contact with the socket due to dirty pins (they are 100+ years old tubes after all). Have you tried switching the tubes and see if the filament for the one in suspect glows?

If you have a spare socket and test wires with alligator clips, or you can connect the wires directly to pins 1 & 4, you can simulate the operation ensuring good contact for the heaters using four (3) 1.5 Volts AA battery. You can easily see the filament glow if the filament is healthy.

It is easy to buy a 01A replacement tube, but to get one that is quiet (let alone a pair) is a challenge sometimes.
My experienced is that measuring pins 1 and 4 (filament) gives you about 0.2 ohms.

I bought about 24 01A/201/301 tubes before I found three quiet pairs (Radiotron, Cunningham, and Ceco) for my preamp. I always buy NOS from a dealer and avoid Ebay.
Goodluck!