Accuphase DP-560

Sorry I have no experience with DP-560, on the DP-550 Accuphase offer three input voltage selection:
Main transformer
J1 = 100v
J2 = 120v
J3 = 220-240v
Standby transformer
J4 = 100-120v
J5 = 220-240v
You can simply measure the DC resistance of the transformer tap to confirm the connections.

imhififan, thank you for providing information. I will appreciate it very much if you would tell me how to change J1 to J2. Do I need to use solders?

You need to cut open or desolder the jumper wire on J1 and solder a jumper wire to J2.

Thank you, imhififan. One more question, do I need to change J4, too?

do I need to change J4, too?

For 120V conversion, no need to change J4.