Proper method for reducing PT voltage?

[ylelevier77]

I have a relatively simple question. What is the best/safest way to drop the DC voltage coming out of my bridge rectifier into my power filter caps? I’m building a TMB Stout and the first filter cap/center tap should see about 356 volts from the rectifier. Right now it’s seeing around 386 volts. The amp was originally a Blues Jr. III (Hoffman hand wired conversion with Allen Amps PT & OT upgrades) and is being  converted into a TMB Stout. The chassis has been pretty much gutted and I’m trying use the existing transformers. Is there a safe workaround? I’d hate to have to buy a new PT & OT. I tried using a 10 watt 200ohm resistor between the rectifier and the first filter cap/center tap. It gave me a usable voltage but was generating way too much heat. Any insight is tremendously appropriated!

[jjasilli]

Power resistor is a good way to drop up to 50VDC.  You only need to drop 30V.  Try a 200 Ohm or 330 Ohm 25W metal housed power resistor, bolt-mounted to the chassis with heat transfer goo.  If you want vacuum tube rectifier simulation, consider using an inductive power resistor.


Another option is a 12V CT'd bucking tranny, but I don't think it's worth the trouble in this case.