Sota Head Amplifer - I need some answers.

I have a Sota Head Amplifer that I need to find a power supply for, but I have no idea what it takes. This head amp is black, about the size and shape of a soda can on a small wood base. It has no model number that I can find. There is a sticker on the bottom with "#170" on it. On the front in gold lettering is "Sota Head Amplifer and Made in USA". On the back are one pair of RCA inputs and outputs, a ground post and a low voltage input of unknown voltage. There are also two switches for ohm load and high/low gain. It also reads "Electronic design by John Curl and Product design by Rodney Harmen". I know that the unit is more than 10 years old. Any information would be of great interest to me. Thank you for taking the time to help.