2Pcs Digital Amplifier Board,TPA3116D2 Dual Channel Audio Stereo AMP High Power Digital Subwoofer Power Amplifier Board 2x50W 5V 12V 24V for Store Solicitation Home Theater Square DIY Speakers

Super fast delivery and a nice board (with a spare). However, read carefully. This amplifier expects an analog input (eg: the headphone jack from a Raspberry Pi). So you can expect a background hiss if you turn the volume up much below the lowest setting. I plan to experiment with adding a small capacitor between the Vin and Gnd to see if it helps, but a bit of hiss is nice in my application (vintage radio). A couple of tips in case they help someone in the future, as this board did not come with a manual: To run in "Mono" mode, you're going to need to blend your inputs. To do this, you attach a 1k resistor to the right and left channels (the red and black wires of the headphone jack). Then you connect both of the opposite ends of the resistors together, and then wire them to both the L-IN and R-IN terminals (eg: they will receive the exact same signal). If you search online, you will find similar instructions which call for 475 ohm resistors and a 20k resistor bridging the end to GND. This is unnecessarily complicated for a weak input signal such as this one and I can confirm that the simpler solution I presented above works wonderfully. Next, if you have a single (mono) speaker, you can connect it in one of two ways. If it's low power (say under 50W or so), then connect it to either R+/R- or L+/L- (doesn't matter which if you blended the signals per above). But if you have a larger speaker (mine is 150W), then you can bridge it by connecting it to L- and R+. This gives you double the power, which is nice, although the hiss might prevent you from taking advantage of it. It is safe to experiment if you have a higher wattage speaker (less power is ok, too much power is not). The amp has a really warm tone, very similar to a record player. Quite a nice sound.

Wired them with 12V DC AT supply, 4 Inch speakers - Input from Android phone full volumn. Barely audible.. When Volumn control turned up more than quarter turn, unit would shut down.. Tried to find and replace the voltage divider resisters to alter gain - no luck - R1 / R2 on this unit are not the correct resisters ands could not find or change gain resisters.. Suggest a brand that has easily changeable gain.. Will add these to my scrap heap. UPDATE: First unit was obviosly DOA (But worked somewhat).. Second unit worked as advertised.. I ordered more..

Good small amp that produces a bit of heat off chip, recommended to put some heat sinks. I 3D printed a small case and put a mini 12volt fan and heat sinks to power my component speakers for a Bluetooth stereo.

I use these for a few projects, they are cheap and easy to set up and cost less than some of the other "kit" type audio amp

For 50watts iexpeced a bit more oomph, but thier small size is a plus for their price point.

I bought a set of these amplifiers and one of them worked great, but the other was DOA. I left a message for the vendor on Amazon and they responded very quickly and replaced the defective amp. As others have noted these amps are powerful and have very clear sound. I used the provided heat sink and that was sufficient for my purposes. I am driving the amp with 5V.

There were a few components that hadnt taken up much solder in the manufacturing process. So just double check all joints before I stalling this. Other than that, this chip puts out a lot of power!! Make sure you use the highest voltage power supply it allows for. Your sound quality will improve alot!

This was just what I needed, using a PA speaker and a hand held walkie talkie made a awesome PA system for our shop. Very load and very clear. Now dont have to carry a walkie talkie all the time while working in the shop