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Plexi/50 output caps

9/22/2000 12:23 PM
Plexi/50 output caps
while trying to bias (shunt method) up a pair of used Mullard EL34's in my homebrew PLEXI/50 at 32 mA, I constantly ran in to the problem of JUST one of the 34's glowing red, (just starting to), when approaching @ 25-26 mA....Interestingly, other matched tube types, I.E., Teslas, Svets,had NO problems whatsoever, achieving my targeted 32mA...SO...I tested all of the resistors whithin close proximity of the bias network on board, and found that all were OK...SO I decided to replace output coupling caps from OD .022's to Vitamin Q .033's....popped in the suspect mullards and voila!...NO GLOW....I'm curious, do the Vitamin Q caps have a "polarity"?

Ray Ivers Frank,What you prob... -- 9/23/2000 2:40 PM