Switching mains voltage on Krell KAV150a

Hi

Is anyone familiar with changing the voltage on this amp? I have two that need to be converted to 120v operation from 220v. The amp has switches that juggle the transformer’s primaries but PCB isn’t labelled for simple interpretation. I’m hoping to not have to spend hours deciphering the board and risking a newbie error.

TIA

Steve
 
Always use bulb tester. Place an incandescent light bulb in series when powering up the circuit after any changes that you make to prevent newbie mistakes, those that we all sometimes make.:headbash: If it is wrong and a short is created, the light bulb will light up and drop out the voltage, limit current so nothing flames out.:hot: if it's correct then the bulb won't light. Use 100W bulb.:up: