Gp16 guitar processor power transformer

[Mikekaast]

Hi forum.
I'am not sure that this is the right forum, but i'll try anyway. I have an old (80'ish) roland guitar processor gp16, with a faulty power transformer. Its a R-core transformer with a minimum of information regarding the secundary voltage. I can see that it provides 10 volts and also have another sec. Voltage. But i cant find out what that voltage is. I have the service schematics but CANT find the sec voltage. There is 3 cabels ( some voltage, 0v and some voltage). Anyone in here maby able to tell me exactly, what ac voltage i need as sec. Voltage when i buy a new transformer. The original transformer Roland used in gp16 is no more avaible in any stores.
Best regards an hope someone can heelp, or maby somone have a working gp16 that they can messure the sec. Voltage on both sec. Windings.
Mike.