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.
John Curl responded to some questions about this unit over at Audio Asylum several years ago. You might try doing a forum-wide search there using SOTA phono amp or SOTA head amp as the key words. Sean
This unit is battery operated.
This unit is battery operated.
I have the same unit. the power supply is 7.7vdc . Of course, mine doesnt work.