• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Help with wiring a Hammond Power Transformer


2007-11-23 11:53 pm
Hi (newbie alert. did search),

I am trying to put togeter an Aikido headphone amp, and I am having a bit of trouble trying to wire up a Hammond 270FX transformer with a 5U4G rectifer tube.

All the power transformers that I've used before (272FX) had center tap on the 5V filament wires. I always took the B+ volatage out of that line (that is how I was taught). Like this:
Hammond / 5U4G Tube
Red wire (300v)- Pin 4
Red wire (300v)- Pin 6
Yellow wire (5v)- Pin 2
Yellow wire (5v)- Pin 8
Yellow/black wire (CT of 5V) - B+

But the 270FX that I just bought does not have a center tap for the 5V filament wires. Where do I take the B+ from?
Do I wire like this?
Red - Pin 4
Red - Pin 6
Yel - Pin 2
Yel - Pin 8
And take B+ from EITHER Pin 2 or Pin 8? Or do I take if from BOTH Pin 2 and 8?