hifi engine

NAD 3020 240v to 110v transformer wiring


I have a venerable NAD 3020 which is a 240v model and I would like it to run off 100v. The mains transformer appears to have taps for 110v and 240v, and ideally I would like to know which colours on the wires to connect. Currently at 240v the brown and yellow are connected to the switch, there are individually terminated Red and Blue (they have end pieces and are not connected to anything) and joined white and brown

I have looked at the schematics, but no information seems pertinent

any help appreciated



alvinj's picture

nad 3020 240 volts

easiest way is to look at the transformer input. there should be four inputs. the two center wires are joined to give 240v ac input. disconnect the two center wires, you have two seperate 110v ac windings. you can test this on a meter.

NAD 3020 wiring

Hi Peter
According to the service manual I have should red and red be used for the UK and red brown for others, but no indication of any blue. I suggest that you try and measure the DC resistance and check when you found half the value brown and yellow.
I have enclosed the primary section of the service manual.
Good luck :-)