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In Reply to: RE: Not to be a contrarian, but... posted by artsybrute on May 05, 2009 at 15:55:24
you're trying to get well below 100 μA. If your tolerances have to be that tight, I would either get a transformer spec'd for this use or go back to a SE circuit and use PJ's points on getting the noise down with cables and step-up location. I'm not comfortable that any scheme will keep things consistently in the single- or double-digit μA range. Do you relly want to constantly fretting over this?
(BTW, I need to do a little more back-of-the-envelope work, but I think that the sum of the cathode resistors used in the garter circuit should be about half that calculated for normal cathode bias. The remaining grid voltage is supplied by the garter, which is where the balancing comes from. With precision NIWW resistors, you should be able to get the tubes very close. Just don't know if you can hope to get them <100 μA close.)
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