MB B Series 15 bass amplifier with sound quality adjustment features. There is some crackling when adjusting the treble knob, but this does not occur during performance, so there is no problem. Also, there is no noise. Please understand that this is a used item as there are tears in the outer box and peeling on the back. - Model: MB B series 15 - Features: CD in, Line out, Headphone jack - Controls: Bass, Voice, Treble adjustment knobs - Power: Switch type Thank you for viewing.