tungsol.comtungsol.com/tungsol/specs/12au7-tung-sol.pdf · 12au7 maximum heater—cathode heater...
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tungsol.comtungsol.com/tungsol/specs/12au7-tung-sol.pdf · 12au7 maximum heater—cathode heater negative with total dc and peak heater positive with dc total dc and peak continued