DAJUNGUO 1002S 2.0 Bluetooth Amplifier Board with Dual TPA3116D2 Chips, 100W+100W Power Output, Wide Voltage Range of 9-24V DC, Bluetooth/USB/3.5m...

The little amp arrived quickly (one day). My old Bose Sounddock stopped working. Replacing boards (especially without knowing which one was bad) is too expensive at around $50 per reconditioned board. I removed all boards from the Sounddock and this amp fit in with some grinding on the tray. I did not use the top and bottom boards that come with the amp. It sounds as good as the original Bose electronics. Bluetooth works nicely from our phones and the old IPOD plays through the headphone jack (although you must turn off the Bluetooth connection from the phone). You can see in the picture how it fit in with the volume knob where the Bose docking connection was removed. If you do this, be sure to keep the heat sink on the speaker cabinet as it makes a huge difference in the sound. I used an old laptop power supply with 19 V 3.5 amps. Also, the power supply jack appeared to fit, but the inner pin is smaller so I had to cut the cord and attach the jack supplied with the amp. I do agree that the wires on the supplied jack are to thin and difficult to work with, but it can be done.

As the title states this amp worked so good I bought a second one. I took four small vintage speakers, rewired them, added the amp inside one of the larger speakers, and put the cables through the back using panel attachments. Picked up a DC converter for power and it works amazing. I left the amp on and the volume to max. I then had to open the speaker and turn the volume down because it was to loud. I have been using it for a couple of months but I need to turn the volume on the amp down some more because it is still to loud. I then took a vintage radio, empty out its guts, and replaced the speaker with two smaller speakers. Reordered the same DC converter for power and it works awesome, sounds great, and looks amazing.

I have the DAMGOO ZK-502T and the ZK-1002 digital amps. They are both great running on a 16V laptop supply. Both provide plenty of volume. I have bought class-D for the TV and for the garage, and I got great results. I needed replacements due to a house fire. ** After a few weeks, mine failed. The BT "ready" signal continued to beep, interrupting music play on the wired input. BT has priority, and if it fails to connect, well, you are stuck with repeating beeps. ZeeBooth Chat support quickly arranged for a warranty replacement with return of failed item. Replaced item works fine. ** The directions for these talk about what size of speakers they will support, and that small speakers require less power. This isn't right. The truth is that larger speakers are generally more efficient. In fact, if you have very large, efficient speakers, you can probably drive them straight out of your computer's sound card. I've done it. Your speakers will make all the difference; get good ones. If you go to a thrift store, only get a name brand like Sony, Aiwa, Yamaha, KLH, Pioneer. Never a lesser brand like Sharp or RCA. I have good quality 8 Ohm Yamaha speakers. If you use good quality speakers, you will not miss bass and treble controlls. Now I'll focus on the differences between these two that I think are most important. ZK-502T pro: bass and trebble controls! I like the flexibility. con: lame stick-on heat sink, probably should lay it flat. Better yet, mount with real thermal tape. ZK-1002 pro: larger screw-mounted heat sink, suitable for mounting in any position. Good, because mine is outside and exposed to the summer heat. pro: neat looking inductor coils, but I can't hear the difference. ZK-502T Current test with 2x 18650 cells (8 Volts) at 50% physical volume Average values: 50mA idle/quiet BT 100mA 50% vol BT 200mA 75% vol BT (with 1 Amp peaks) 600mA 80% vol BT (with 2 Amp peaks) 2500mA peak at 100% vol BT Recommended for long battery life: 2x 18650 cells with 2500mAh capacity, 12 to 24 hours runtime depending on volume. Better than some products off the shelf. Common A/C power supply recommendations: Minimum: 9V 1Amp Also suitable: 12V 3Amp, 16V 4Amp For 6dB greater distortion free volume: 19V 4.5 Amp Should probably not use less than a 12V supply with the 1002. The biggest difference between power supplies is that the audio is 6dB louder at most at 16V plus. The power regulator stays cool at 9V and begins to heat up at 16V. The main chip stays cool at 9V, and at 16V heat begins to build up as it is slowly dissipated through the board and components. I used a thermal camera to check this, and max temp I ever saw was a moderate 100 degrees F. Loud volume with a weak 9V supply can cause it to fail and restart. So only use a weak 9V supply if you plan on listening at moderate levels. With my 16V supply, there is sufficient current available for very loud music with no interruptions. Higher voltage is required for more volume, but results in more heat. At 16V, temps reach 115 degrees F. Semiconductors can take much more heat, and the main TPA311 chip has thermal protection. So these measurements are only for your information. The supplied stick-on heat sink didn't heat up much -- it is for show. Heat is also dissipated from the main chip through the board, however. I scraped off the black adhesive and used thermal tape instead -- with better results. I recommend you do this if you use a 24V supply. The reason I tested current usage was to confirm what I suspected -- that these amps are very efficient and require little power. I also wanted to know my battery life. I recommend 2 18650 cells. More than that will offer more volume, but will shorten battery life, as more power will be wasted in the power regulator. My AUX audio source is a Sony walkman mp3 player. Your source and/or a higher voltage power supply could get you more output power. But I believe it would never be close to 25 Watts, and this is something we should all be aware of. Bluetooth devices with Aux capability usually have better performance on BT. This amp is no exception. Idle power use is lower and audio is clearer at low levels. Current peaks at 2A before distortion sets in. Any supply with at least 2 Amps and a minimum of 9V should be good for a quiet location, 16V if a bit more volume is desired for a loud location. (edited) Good luck and have fun! -Chris

This amp provides satisfactory music reproduction - nothing like a Crown or a Marantz with your classic vinyl, but adequate - at literally a slave labor price. If you haven't priced mini amplifiers lately, you will be pleasantly surprised by the amps with the miniscule TI TPA3116 chips. That said, it could be better at very little expense. Anyone within 10m can shut down your AUX input by pairing a device to the amp Bluetooth. This amp cannot disable Bluetooth, unlike other amps that toggle between Bluetooth and AUX input by pushing or pulling the volume knob. But those amps cost a few dollars more. The rated volume depends upon the input power, that is, upon the voltage and amperage provided at the input power jack. 4.5a at DC 24v is reported to produce 110w PMPO (about 55w RMS) for each of two 4 ohm speakers. But the circuit board has "5-27v" stenciled at the input power jack. Don't count on it. The specs show that 24v is the maximum input voltage allowed, with 5a recommended to prevent clipping. I tried DC 25v on my amp, and it managed to emit a "power on" beep before the amp overvoltage protection shut it down. So don't expect the 125w x 2 PMPO, 62w x 2 RMS, that DC 27v would produce. But then again, ymmv. The amp format is about the area of a credit card, so attaching the speaker wires requires small fingers or great patience. There are no mounting holes on the bottom, and only the volume knob to secure the amp to the faceplate you provide. To my shame, I was reduced to securing the bottom with hot glue. But it is what it is. What it is is most likely the most tech you ever bought for just $23.