by EWBrown » Tue May 11, 2010 2:53 pm
The cathode resistors' value would have to be increased, to accomodate the 45's somewhat more "modest" plate dissipation ratings and max P to K voltage.
I'd aim for between 1500 and 2000 ohms, 10 W for each 45. Other than that, everything else should be good to go... Probably want to keep the
plate current at 30 to 35 mA, in order to to prevent a case of red-plate-itis. They are more delicate than the modern production single plate 2A3s and 6B4Gs, so they need to be treated gently. The higher plate resistance of teh 45 may dictate using a higher impedance OPT primary, as well, at least 5K, vs 2.5 to 3.5 K which is the norm for 2A3s and 6B4Gs.
I haven't yet tried any of this, but I have seen postings over at BH over the years, about converting Paramours from 2A3 to 45 operation. I have one single NOS 45 in my stash, and have been too "cheap" to go find it a mate.
IIRC, the stock (2A3) Paramours use 1K for cathode resistor - I have the newer version PIIs, and can flip one over for a peek under the chassis plate, to verify this.
/ed B
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