[CButterworth]

I have just completed my Aikido preamp, and have got the hum down to tolerable levels.  However, I have now realized that maybe I need to do something with the center-tap of my Hammond transformer.  The transformer is 125-0-125 and I am using the 125 sides to put 250VAC into a dioide-bridge rectifier.  I end-up with about 360VDC, which I roughly what I expected from the cap-input filter system.  My heaters are run from a separate 6.3VAC transformer, the center-tap of which is referenced to 1/4 of the B+ voltage.

So, should I ground the center-tap of the 125-0-125 transformer?  Ultimately, I want to float the PSU/signal grounds via a diode-bridge/cap/resistor system to Earth.

I'd appreciate any help,

Thank-you,
Charlie

[Occam]

No. Assuming you want that 360vdc B+ plate supply, you want the transformer wired to produce 250vac, with those 2 125vac secondaries wired in series, with the center tap left alone.