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Original Message
RE: Doesn't the Dynaco PAS use a voltage doubler for rectifying the filaments?
Posted by DAK on June 12, 2017 at 16:52:27:
Series, parallel arrangement. I was just checking that, and on each circuit board, the 2 tube's heaters are in series, and the other circuit board is paralleled with the tube heater again in series. I have not noticed this type of an implementation in other preamps or amps. Is this kinda clever or mostly and economy move or both? I really did not notice this before and the PAS was the first tube preamp i owned over 30 years ago, which i was given by my father in law. And this explains why i always had trouble rebuilding that circuit, because i failed to notice that it was a voltage doubler and when rebuilding, its design always threw me off.