12-14-11: Atmasphere
In practice, tubes with leakage can buzz ...
Ralph, assuming you are referring to heater-to-cathode leakage, how many megohms of leakage resistance would you consider to be the threshold of acceptability for a 6SN7, as measured say on a vintage Hickok tester?
Also, based on your experience is it expectable that a tube showing marginal leakage (perhaps 2 to 5 megohms, for example) during its early hours of use will improve over time?
Thanks! Best regards,
-- Al