The inputs of the amplifier go through 1.0uF capacitors, so they are fully ‘differential’ – if you don’t have differential outputs, simply tie the R- and L- to ground. The outputs are “Bridge Tied” – that means they connect directly to the outputs, no connection to ground. The output is a ~300KHz square wave PWM that is then ‘averaged out’ by the speaker coil – the high frequencies are not heard. All the above means that you can’t connect the output into another amplifier, it should drive the speakers directly.

Comes with a fully assembled and tested breakout board with 1.0uF input capacitors. We also include a dual mini DIP switch for setting the amplifier gain on the fly, 3.5mm screw-terminal blocks so you can easily attach/detach your speakers, and some header in case you want to plug it into a breadboard.

Features:

• Output Power: 2.1W at 4ohm, 10% THD, 1.4W at 8ohm, 10% THD, with 5V Supply
• PSRR: 77 dB typ @ 217 Hz with 6 dB gain
• Designed for use without an output filter, when wires are kept at under 2″-4″ long
• Four pin-selectable gains: 6dB, 12dB, 18dB and 24dB. Select with the onboard switches or by setting the G0 and G1 breakout pins
• Excellent click-and-pop suppression
• Thermal shutdown protection
• Independent channel shutdown
• Low current draw: typ 6mA quiescent and 1.5uA in shutdown mode

Documents:

• Adafruit Tutorial