Voltage conversion of Accuphase E-650

Does anyone know how to convert voltage of Accuphase E-650 100v to 110/120v? Or does anyone provide information on voltage conversion table of Accuphase E-650?
I went ahead and did this myself and tested successfully with a dim bulb tester.

The amp sounds fantastic! It is somehow both crisp and clear, yet rich and slightly warm, with great texture and soundstage depth.

For others who might use this thread for reference, here are some more photos of the board removed, ready to work on, and post-conversion:


Initially I thought it was one big board so I was going to take it to a pro. After being turned down by my usual tech (turns out they are an authorized Accuphase repair center and thus were told by Japan they couldn’t do it), I took another look under the hood and found that the connectors are actually on a smaller board secured by just 3 screws. I unplugged the 2 harnesses, 3 wires (blue, yellow, brown), and boom--easy access.
Is there any guide how should 230v/240v label should be? I am eyeing for a 220v pre-owned unit but need to convert that into either a 230v or preferably a 240v version
Appreciate some advise

Hi everyone, 

I have the E-600 amp and I am thinking of converting the voltage for it. 

Does this conversion change the sound quality? 

If I don't have dim bulb tester, is there any other way to test?

Thank you.

@imhififan My amp is E-600 (not E-650 as others’ in this thread). I am trying to convert the voltage from 100V to 120V.

Could you check the 3 pictures below and advise where these K connectors need to be moved?


Many thanks!