TWS Bluetooth Amplifier Board, PEMENOL DC 7-24V 100W Mono Audio Power Amplifier Module with Box Matching Function Support AUX/Bluetooth/USB for DIY Electronic Kit Car Home(ZK-1001B)

Very good Class D Amplifier for this priceThis is class D amplifier (sometimes it is called “digital” amplifier.The advantage of class D is very high efficiency >90%.The disadvantage is higher distortions, but in most applications, it wouldn’t matter, and people wouldn’t hear it.I powered the amplifier from the bench Power Supply and tested it at different voltages, measuring the input power (Pin, W) and the output power (Pout, W) at 4 Ohm load, using sinewave generator at my phone over Bluetooth, as the input signal.Two Oscilloscope channels were connected to two output terminals (this is a “bridge” amplifier and load is connected between two active outputs). The output peak-to-peak voltage (Vp-p) was measured.The output power was calculated Pout = ((Vp-p) * 0.7)^2 / 4.Volume was adjusted to provide maximum output amplitude without clipping.Results (1kHz, 4 Ohm):Vin = 12V, Iin = 1.3A, Pin = 15.6W, Pout = (11.0*0.7)^2 / 4 = 14.8W, Efficiency = Pout / Pin * 100% = 95%Vin = 16V, Iin = 1.6A, Pin = 25.6W, Pout = (14.0*0.7)^2 / 4 = 24W , Eff = 94%Vin = 20V, Iin = 1.95A, Pin = 39W, Pout = (17.0*0.7)^2 / 4 = 35.4W, Eff = 91%Vin = 24V, Iin = 2.25A, Pin = 54W, Pout = (19.8*0.7)^2 / 4 = 48W, Eff = 89%• Note: The Amplifier output was shutting down after 10 seconds and coming back in a few seconds as a result of over-temperature protection., because the Test was conducted with the continues sinewave and the amplifier is not designed for this condition. Normal audio signal has significantly lower average power.Result (1kHz, 3 Ohm):Vin = 24V, Iin = 2.98A, Pin = 71.5W, Pout = (19.6*0.7)^2 / 3 = 62.7W, Eff = 88%• Note: Over-temperature protection was shutting down the output after 1 second and coming back in a few seconds.•Frequency Response:20Hz – 18kHz• Note: My Generator lowest frequency is 20Hz and I couldn’t test it below.• There is no output signal above 18kHz.What I like:Small sizeQualityEfficiencyBT and analog inputWhat can be improved:The heatsink is attached with double-sided tape, which is not very secure and doesn’t provide good heat transfer.Conclusion:Very good class D amplifier for the money

Although it doesn't come with the instructions on how to connect two together (TWS Mode), I found what I believe is that resolve.Connect One amp to a bluetooth source (phone, mp3 player, etc), and leave the other disconnected from said bluetooth source. Click the potentiometer (volume knob) three times on the amp that is connected to the source. Then click the second/other (disconnected) potentiometer three times. Both amps should show a rapid flashing blue/red light indicating they have activated 'pairing mode'. In 1-5 seconds you should hear an audio sound from both amps/speakers. The flashing lights will then show synchronized slow flashing.Note: Although they are now in 'tws mode' volumes are still individually maintained.I have purchased a total of 19 of these amps over the course of 2 years (used in bluetooth speaker boxes). Every Single One is still in perfect working order. When using the correct power and speakers, these things are monsters of sound. I highly recommend.Buy one or two, and make up your own mind.

Tws works good. Took me a few times to get it to link. Directions from this page help. The package came with no written directions.We will see how the amps hold up over time.

Great power output for the size, doesn't use too much power. The TWS is a pretty cool feature for pairing 2 of these unit together.This is exactly what you're looking for if you're building a boombox/rugged speaker. I would absolutely recommend this one for use in single speaker, lower wattage applications. Especially when battery powered. Protip, run this at 24v for max power output

Nice amp with Bluetooth built in. You will need a hefty power supply to get great sound out of it.

Endless loop of beeps trying to connect and fail to connect. Still using as they are simple amps and sound great, they do the job if you do not care about linking two together

I build and gift Bluetooth Boom Boxes to Vets and under privileged young people. These help make that possible because of price and quality

My first impressions with this were quite strong, but after just a little bit of use I am having a major problem. I am using the 3.5mm audio jack for input, but a second or two later after my device stops playing the amp seems to be doing some sort of audio input search. Is there a way to tell the amp to just stay on the audio jack and not switch?Edit: Pemenol reached out to me and was able to assist with some help trouble shooting. Unfortunately my problem wasn't resolved, but I am confident in saying that it isn't from this product. Main take away, if you are looking for a simple and lower budget amplifier I would recommend this.