dozerman,
Re-reading post #11, it seems you may be a bit confused about series/parallel filament wiring.
I start at #1 then # 1 to the next and out of #12 of the same one to #1 of the next and so on until I finish with the last tube #12 going to ground. Correct?
Just to be as clear as possible, the way the above is written would be strictly series wired filaments. If your 4 tubes were wired in this manner, the 3rd and 4th tube in the series would have 0 voltage on the filament. (Experts, Please chime in!)
See the filament wiring section below of the following link from CBTricks. It is a Maco 200B with 6LB6's.
http://www.cbtricks.com/Amp/maco/maco_200b/graphics/maco_200b_redraw_sch.gif
V1 & V2 above are in Series with V3 & V4 also in series but parallel to V1 & V2. Or Series/Parallel. (This is what I meant by referencing "Tube 1, Tube 2" etc in post #13.)
Please don't misunderstand my intentions. I am not trying to be "Holier Than Thou" or anything like that. I make my share of mistakes (See post #4 and about every other post I have made!
) Comes with the Old Age thing. Computing with one hand is very slow and chockfull of do overs! I tend to believe my memory instead of researching due to the cumbersome task with my limited ability. (In other words-"Classic Laziness!)
I believe wiring all 4 of these tubes in Series and turning on the high voltage may fry at least 2 of your "cheaper" replacements for the 8950/M2057. Last I knew these 6LB6's were about $40.00 each! Too rich for my wallet.
AND
ABOVE ALL ELSE-BE VERY AWARE OF THE HIGH VOLTAGES IN THIS UNIT! PROTECT YOURSELF AT ALL TIMES WHEN WORKING ON THIS UNIT! DISCHARGE THE CAPS, PULL THE FUSE AND PUT THE POWER CORD PLUG END IN YOUR POCKET TO BE SURE YOU ARE SAFE!
I have been lucky enough in the past to survive unscathed a 400vdc jolt (from all else-the awesome Golden Eagle Mark lll). It wasn't pleasant and I vowed not to repeat that stupid mistake. The best lessons learned are taught by repetition and/or Trauma Impact!
Please also seek advice from some experts. There are many of them on this forum. I am not one of them. Just a lucky Old Dude who is still kicking despite all the Trauma Impact lessons I have learned in life.
Have fun, Good Luck and Learn Things!
73's
David