Accuphase E-408 voltage conversion

Hello,

Maybe someone has experience in converting the voltage for the Accuphase E-408 amplifier from 100 volts to 230 volts?  I tried to find this information on the forum, but without success. 

I would be grateful for a photo of the board with the location of the jumpers for 230 volts.  

Sincerely, Victor.