Accuphase E-408 voltage conversion

@zeptul please counter check if the jumper positions are correct.

If the jumpers position are correct, the setting should be as below:

100V mains =  J5, J7, J9

120V mains =  J4, J6, J9   

220V mains =  J5, J8

240V mains =  J4, J8

Before changing jumpers, measure resistance across C2, after changing jumpers to 220 or 240V setting, the resistance across C2 should be more than 4X higher.

BTW, 220/240V mains also required changing fuse F2 and soft start resistors jumpers setting. Please provide a photo of showing J1, J2 and J3 so we can figure out its setting.

I also strongly recommend connect a Dim Bulb Tester or an 100watt incandescent light bulb in series to power up the amplifier after voltage conversion. If anything goes wrong, the bulb will simply light up instead of dim down to prevent damage of the amplifier.

@imhififan wow - that is nice work sir.

@imhififan ​​​​​​

Thanks a lot for your real help!

Later I will disassemble the amplifier and check the position of the jumpers.

P.S. For some unknown reason, links to photos in my previous posts have been removed.

@imhififan 

I checked everything. You absolutely accurately indicated the position of the jumpers!

Before changing jumpers, resistance across C2 is 0,5 Ohm.

After the prayer, I will start voltage conversion :)

As you advised, I will turn it on through the light bulb.