I used this for distortion on my guitar and bass until last year. It has a unique distortion that I liked, but I'm selling it to organize my equipment. Operation has been confirmed with a power supply. Basically, returns are not accepted, but please contact me if there are any problems upon arrival. DC9V center minus - Model name: DST-5 - Function: Distortion - Controls: LEVEL, TONE, DIST - Country of manufacture: Korea