Accuphase E-260 Voltage Conversion (100V to 230V)

Hello Forum Members,

I have an Accuphase E-260 Int. Amplifier wired for 100V wall outlets. I am trying to convert it to 230V. From various threads on this forum, I could figure out that this unit has quick connect terminals for winding wires. It was less daunting to find that out!
Can somebody pls help with it's 230V wiring diagram?
(attached: existing taps for 100V wiring)

Thank you.


Hi @imhififan 

I have successfully converted my E-270 from 100v to 120v thanks to your help. However, I keep wondering how come the conversion doesn’t affect the voltage output that goes into the internal components?  Is the internal power transformer designed to provide the same voltage output to the components regardless of the input, whether it’s 100v or 240v ? Thanks again for your help. 


You're welcome, glad I could help.

The function of the power transformer is to convert the mains voltage into the operating voltage required by the amplifier. It all has to do with the "turns ratio" of the primary to secondary windings. For example, the amplifier requires an operating voltage of 50V, while the mains voltage in Japan is 100V. To obtain 50V voltage, the primary and secondary winding turns ratio should be 2:1. For 120V North American mains, to obtain the same 50V secondary output voltage, the turns ratio should be 2.4:1; for 240V countries, the turns ratio should be 4.8:1.

Accuphase designed the power transformer primary winding with different turns ratio taps so we can connect the mains voltage to the designated taps to get the same secondary winding voltage.

Hi @imhififan

Sorry for bugging you again.

Since my E-270, which I converted to run on 120v, won’t receive any service support in the US, I’ve been careful to ensure it lasts as long as possible. To achieve this, I always unplug the power cord when it’s not in use. My reasoning is to prevent the primary windings of the internal power supply from being constantly energized with 120v, which could potentially shorten its lifespan by continually converting it to 50v.

Am I correct in thinking this way? If the power switch is responsible for supplying 50v to the internal components, then unplugging the power cord would indeed help preserve the transformer’s lifespan.

On the other hand, if the power switch is responsible for passing 120v directly to the primary windings, and considering there’s a fuse next to the power switch, logic suggests that leaving the power cord unplugged in when not in use might not be necessary.

Thank you


The power switch is responsible for switching the mains voltage, unplugging the power cord when not in use will not help.

If you want to avoid wear and tear on your power switch and minimize stress on  power supply components during the turn-on process, my suggestion is to install an outlet with a built-in switch and a simple resistor soft-start circuit.