Hopefully the new owner will only need a user manual! But first off they need to figure out, what voltage the unit is set up for, just incase someone went into the transformer and changed it over to 110. I would be a real bad if someone had changed the voltage to 110 and then the new owner just replaced the plug and plugged it into 220.
I don't know anything about the amp and even if you can change out the voltage, but if I got it, that would be the first thing I did, try and figure out just what voltage it is set up for.