These are a great amp for beiginners and low volume home use. The BC20 features a True Class A preamp which avoids cross over distorition & achieves warm & articulate Bass tone and Low Z circuitry that provides a very low noise floor and is the difference between enduring audible hiss and enjoying a pleasant tonal experience. It has two inputs for Hi & Low gain, suitable for 2 instruments at the same time. This is ideal in a teacher / student situation, warm up back stage or small rehearsals. The BC20 also features DDL (Dynamic Distortion Limiter), a limiter circuit sensing power amp distortion rather than gain level. This maintains amp distortion at 0.03 % ensuring the amp remains distortion free all the way to ten. There is a Stereo Aux input optimized for MP3, CD player & similar devices. The design also features a deeper cabinet with a bass reflex design for deep bass response.