Royer mod with T Bone SCT800 psu

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globule_655

Member
Joined
Jan 22, 2012
Messages
12
Hey everyone !

I'm building myself a new mic following the Royer mod schematic for the head amp. As I have a T Bone psu that came with a SCT800 tube mic I used as donor body for a previous project, I thought I'd use it.
Stock, it gives 200V for B+ voltage, regulated by two 100V zener diodes as well as 6V regulated by a 7806.

My first thought was to just remove one of the 100V zener and replace the 7 pin XLR (already gone for the other project anyway) with 5 pin XLR. But now I wonder about 2 things : will the zener handle the power/current on its own ? Maybe I should replace it with two 50V zener in series (same as stock but half value) ?
Second I wonder about the current capability of the psu as the CV465 tube I have has a much higher max cathode current than what the 12AX7 the psu was built for asks...

Any ideas ?

Thank you very much in advance  ;D
 
Ok so I went on and tested the thing. I used it on a recording session on a variety of sources so it stayed on for quite a few hours  (something like 8 hrs) without any hicups.
Save the fact I don't consider this a time long enough to be sure, I still can assume it works and won't set the studio on fire after a few minutes.
Still, I'd rather know if I'd better change something or be prepared to repair the psu and/or the mic every 3 or 4 days...

Cheers !
 
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