Effect fo filament supply on tube life.

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Y.F.C.

It's a problem that bothers me for a long time. Some say that reducing filament supply voltage to 95% of specifed value may prolong the life of small signal tubes. Despite its effects on sonic performance, can it be harmful to the tubes due to inadequate cathode emission capability?
Most datasheets specify the +-5% limitation on filament supply voltage deviation from normal value. What if reducing it further down to 90% of normal value? Well, I think reducing filament supply may lower the heat produced in the tube, which may seem to prolong tube life. However, under lower temperature the cathode may produce less free electrons than needed, and get deteriorated. So do you think it is generally good to reduce filament supply volatge?
And one more: I remember I have seen a post here pointing out AC filament supply is inferior to DC supply when tube life is a major concern. What is your opinion about this?
Thank you all. :D

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Topic - Effect fo filament supply on tube life. - Y.F.C. 02:44:56 07/02/00 (8)

Re: Effect fo filament supply on tube life. - Uncle Ned 01:22:38 07/06/00 (1)

Re: Effect fo filament supply on tube life. - mccotter 06:49:46 07/06/00 (0)

Re: Effect fo filament supply on tube life IN MY PREAMP. - Carlos 16:16:19 07/04/00 (0)

Re: Effect fo filament supply on tube life. - Triodethom 10:53:48 07/04/00 (0)

Re: Effect fo filament supply on tube life. - steve 14:42:54 07/02/00 (0)

Re: Effect fo filament supply on tube life. - mccotter 08:15:32 07/02/00 (0)

5% is not big deal - Victor Khomenko 07:36:10 07/02/00 (1)

Re: 5% is not big deal - Jack DuMoulin 11:03:32 07/02/00 (0)

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