The Modern Device LM4889 audio amplifier breakout board uses one of National Semiconductor’s “Boomer” amps. It uses what in the industry is referred to as a “bridge-tied load”. This is an efficient system that increases the total amount of power available to the speaker. It also eliminates the need for an output capacitor, (like in the LM386) which tends to be bulky and can limit the low-end response. It has a shutdown pin to put the chip to sleep, just in case you’re trying to build a super low-power microcontroller application that spends most of its time sleeping.
This is probably not loud enough for a good dorm-room dance party but more than loud enough for a personal appliance, such as amplifying the Fluxamasynth Shield, or an Adafruit Wave Shield.
All this in a really small package. Here are some specs.
|Power Out||THD & noise||VCC||Load (speaker ohms)|
|1W||.2%||5 volts||8 Ω|
|.4W||.1%||5 volts||8 Ω|
OK, it’s not quite up to CD quality sound, but then neither are most of your other electronic appliances (such as cell/smart phones) these days. Pop music still seems to be doing fine.
Plus dig the price.
Ships with a two pin, and a 4 pin male header, and a 200K pot which are all not soldered onto the board. All other parts are assembled and tested and ready to go.