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(Yet another) HV power supply using the Tentlabs MEC

(Photos are hyperlinked to higher resolution images - just click on them).

I designed this power supply board to power the high voltages for use in a SE amp using the rare 4304CB / VT-62 / or 834 triode.  It can be used in many other applications as well. It can generate a high voltage B+, a voltage of 1/2 the B+ (useful for a screen grid or driver supply), plus one other rail that is typically used for a negative voltage, but can be used as a positive supply as well.

The board as I used it generates voltage of 450V, 225V, and -100V. It does this using a center tapped HV winding plus a second isolated winding for the negative supply.  Instead of big chokes I used Tentlabs MEC-200 electronic chokes.  These things are awesome... you can order them directly from the Tentlabs online shop. (Note that it seems the MEC-100 has been replaced with the MEC-200).

Here's the schematic (or download a PDF file of it):

Pretty straightforward...

I installed 4.7 ohm resistors at R1 and R2.  I don't think they are needed but it was easier than a wire :)

I powered this from a custom transformer that provided 360 VCT and 87V.  With that I got about 450V (load is 100mA), 245V (load is about 20mA), and -100V (load is about 20mA).

Here's the PCB layout:

...and the bare board:

Here is the parts list (BOM, bill of materials) in .XLS and .PDF forms.