Musical Instrument Automatic Selector Switch

Model AS-3

The AS-3 is an automatic ABC switch. It allows the musician to play three different instruments without having to manually select which is going to the amp or pedal bar. There is no need to remember which instrument is connected to which stomp switch. Just pick up and play one of the three instruments and the AS-3 will automatically detect and switch to that instrument virtually instantly.

AS3 automatic ABC selector switch case from view of LEDs and input jacks

LED indicators are provided to indicate which instrument the AS-3 has locked onto. In a typical performance using the AS-3 the musician doesn't need to care which jack is selected since it is the one he is playing.

The three inputs of the AS-3 can be used with guitars, violins, keyboards or other similar musical instruments. The AS-3 inputs have high impedance as to not load or change the tonal qualities of pickups. The inputs are independently buffered before being switched. The output is buffered to drive the amplifier or pedal bar. The AS-3 signal path, buffers and switches, uses JFET technology for clean, low noise performance.

The AS-3 turns on when a patch cord is plugged into the output.

The AS-3 runs for hours on an internal 9V battery. A DC power jack can be used with an external 9V DC 2.1mm wall adapter. The polarity standard used is pin negative and barrel positive. The AS-3 has internal precision regulation so it can be used with standard unregulated or regulated 9VDC wall adapters. The internal battery is disconnected when using the power jack. The battery is easily replaced via the battery box drawer.

The AS-3 was engineered in the U.S.A.

AS3 automatic ABC selector switch case rear view showing battery box, output jack, and power jack

Links to more information

Take a look at the insides
Theory of Operation - How It Works
Demo Video


Input Impedance: 1 Mohms
Output Impedance: less than 10 Kohms
Gain: 0db
Power: 9V Battery or 9V DC Wall Adapter