The PHILCO Phorum

Russ.  I think you are right about the leakage.  As I recall, when I tested the tubes that I got from Bob,  several showed leakage on my tester even though they were supposed to be NOS tubes.  Probably the point is they are new OLD stock tubes!

It is likely that one of those is causing the pop on warm-up. You might try shuffling them. On my Panatrope a strong 1st audio is always noisy - or hum. So I just use a good one ~900 gm, no problem