Accuphase E-280 Voltage Conversion (100V to 120V)

Has anyone done a conversion on the Accuphase E-3000?

Hi everyone! I finally managed to publish a post 😄.

My name is Pietro and I'm Italian. I've been a fan of the Japanese brand for several years, and after several devices, I finally got to the combination of a preamp, a Class A power amp, and a CD player in my main system, all Accuphase.

Yesterday I purchased an E-280 (in Japan) for my second home system. As soon as it arrives, I'll upload photos of the faston connectors. I hope you'll help me convert it from 100 volts to 230 volts, especially the legendary forum member @imhififan 

@sonicrage 

The Accuphase E-280 power transformer has two primary windings, connecting the windings in parallel will produce a 100V or 120V primary, and connecting the two windings in series will produce a 220V or 240V primary.

Above is the 100V connection. From the picture we can see that it comes with 7 wires from the power transformer which are blue, brown, yellow, black, purple, red and orange.

There is a blue capacitor soldered to the connector block and its two pins are connected to the main voltage.

For the 240V setup, we need to determine which colored wires are 1, 2, 3, 4, 5 and 6 by measuring the relevant resistance with an ohmmeter.

The yellow wire is connected in series with the thermal fuse to wire #1 inside the transformer, so the resistance between the yellow wire and wire #1 should be close to 0Ω. From the picture of the 100V connection we can determine it should be the blue wire or the brown wire.

The resistance between wires #1-#3 should be higher than the resistance between wires #1-#2. We can use the same method to determine the color wires of the other primary winding are #4, 5, and 6.

Once we have the two sets of primary windings figured out, the connections are simple and straightforward.

@imhififan Thank you so much for your thorough explanation.