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

It works perfectly well, and the output is really clean.

Been an audio guy for many years so I was a bit skeptical of these coming from full rack size class AB stuff, but these are pretty impressive. They're not "hi-fi" by any means but they sound really good for what they are, and as others have mentioned they don't even get warm enough to bother slapping a little heat sink on. I wired up the first unit to run from a USB-A plug, with a standard 1/8" aux plug for input, and alligator leads for outputs. Connected it to a few different drivers and speakers for testing, threw some awkward passive crossovers at it, drove a 2 ohm load with it. Thing barely got warmer than room temp. There is a bit of noise on the output, quieted some with a small cap across the power input, would probably be better in a small shielded or metal project box, but again, it's really impressive for the price. The sound isn't as full or powerful as a "real" amp, but for something like a mini bluetooth boombox or a small project that needs to make noise, this would be ideal.

I've been using this for 8 hours a day for the past month. I have it powering 2 - 16 ohm speakers (about 1.5W total between both channels). It hasn't had any issues at all. It doesn't even get warm to the touch at maximum volume for 8 hours straight. Definitely great value. I haven't tested the other 4 boards but they all appear to have the same build quality.

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.

These work great! The sound was a little tingy so I added some capacitors and it sounds great now. They work well with the little 5v Bluetooth modules found on Amazon.

You kind of get what you pay for very much static had to use how to use a bunch of capacitors and resistors just to get it to sound somewhat bearable.

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]).

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.

Segnalo che ho ricevuto 10 amplificatori come da titolo (la descrizione a volte dice 5 e a volte 10). Piccolo (come una moneta) e funzionale, non è praticissimo da usare con breadboard (i contatti non si allineano con i buchi di una breadboard standard) ma fa il suo. Ne ho provati un paio e funzionano, e non ho sentito evidenti e gravi distorsioni sul suono.

This little amplifier module really packs a good punch. Decent sound quality for smaller diy boombox projects. I'd buy again.

funcionan perfectamente y con sonido nítido alimentados con un cargador usb de movil

First off, the price was very good for a small 3watt + 3watt amplifier. In fact you get 10 cards which I didn't need. I would have preferred to buy say a couple for a lower price. Anyway it is compact with no large coils or electrolytics. This is quite innovative for a class D amplifier. It is still a good idea to put some ferrite beads on the wires though to reduce RF interference. It is powered by 5v, probably a USB outlet and has a reasonable volume. 3 watts is into 4 ohms 10%THD. Each board is stereo. So good for desktop speakers etc.

Bought six of these for general purpose amps in a school electronics lab. So far have built two (using a DC to DC converter from elsewhere on Amazon to provide 5V whatever the students try to connect to it) and they've worked really well. Gain is just enough to drive the amp into clipping with the input driven from a mobile phone headphone lead. Mounting is a little difficult as the board is so small. My first two are hot glued on for the time being, but am going to use self adhesive foam pads for the remaining four.