console radios as guitar amps

I just purchased 3 old console radios: Philco 51-1733, Motorola 7F-11, and Bradford SL-480(8?). Want to try to use phono connection for a guitar, turning console into small practice amp. Anyone ever do this? Im not a tech, but can follow directions. Obviously, I still have to determine whether these things even work! I havent plugged them in yet, and I hope no one already did.