Eleca Guitar Preamp, GPM-1Pro This small box works as Guitar Preamp, turns any audio system into a Guitar Amplifier. Clean/Distortion channel Treble/Bass EQ adjust Build in 27 Distortion Modes Level Control  Send/Return Effect Loop RCA line Out 1/4" guitar input and output jacks Headphone Jack internal headphone driver build in digital reverb 9V DC, Battery not included Can also work as Headphone amp and a Active DI