HiLetgo 5pcs PAM8403 2x 3W Mini Digital Power Amplifier Board AMP Class D 2.5-5V Input

Replaced the failing circuit, installed the new on (now have 4 spares) Works great.

I'm using this for a RetroPie build and the testing so far for sound quality has been great! Seems to push a decent amount of power for such a small board and especially handy because it can run off the battery directly, doesn't need to get boosted to 5V! Doesn't save too much because the efficiency is generally pretty high, but eliminates the extra current required for the boost!I just ended up using some cheap-o speakers I scavenged from an old bluetooth speaker set and have had no complaints, especially for the cost!

Sounds good for my application but note that the output contains the PWM signal from the amp, which is a noisy 250KHz square wave. This is well outside of the response range of your average speaker, and certainly not audible, but it's definitely there. If it affects the audio or not, I can't really tell.Since it's not stated here (but is in the PAM8403 datasheet), make sure your speakers are connected BEFORE powering up, and that your input signal is within -0.3 and +0.3V. Otherwise you could damage these.These benefit from good placement in your project to avoid picking up noise. Adding ferrite beads on the outputs wouldn't hurt either. Read the PAM8403 datasheet and look at the sample circuits to get the most out of these.For boards like these that don't have mounting holes, I use the pins to provide mechanical connection as well as electrical. Unfortunately, the pins aren't well aligned to do that on a standard perfboard. The outputs are perfectly aligned, so they fit well, but the input and power connections aren't. You can bend your pins slightly to make it work, but it's crazy that they just didn't align them, it's literally only off by a mm or less in each direction.

Love these little guys - tiny, simple to wire up and enough juice to make things happen. Great for prototyping, etc. I only wish there were a mounting hole or two.

When I bought these they came in a tiny foil bag. I used one of them on two tiny 3 watt speakers. When I tested them I noticed that it was extremely ‘scratchy’. When the speaker would hit low notes they would just get really muffled. Genuinely considered returning. But because they were five bucks decided to keep them. Ended up getting a surround sound system with no amp or receiver. Remembered I had these and used them. They all worked perfectly. So a word of help is use these on bigger more power hungry speakers (my surround sound using 60 watts from each amp) so they aren’t ’scratchy’. To clarify if you using this on tiny 3 watt speakers and they sound really bad especially on those bass notes, hook the boards up to more power hungry ones (I’m using them on two 30 watt ones[plus a woofer]).

I needed a small cheap amplifier to test out some custom speakers I built and this does the job! Great sound output and the performance blows my mind! You can squeeze in small pitch 2 pin terminal blocks for solder free connections for power and audio out.

These PAM8403 amplifier modules aren't going to win an award for audiophile grade high fidelity, but they sure are fun for bluetooth speakers and ~5v applications. They're tiny in form factor and dirt simple to wire. I've used them for bluetooth speaker wiring with a simple stereo to mono summing circuit. It's really easy to build at least a workable prototype with them. It's hard to beat the price with having 5 of them, too.

The amplifiers sound good and pair well with small electronics projects. However, one of the amplifiers I received was DOA, so make sure you test each amp before soldering it into your project.