ZK-1002

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. Amazon 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

I have it driving two 4” 30 watt rms car speakers, powered by a 12v, 3.5 amp wall wart I stole from an old router. Using car speakers both let me use coax 2-way speakers and get the most wattage out of the power supply. It works great. It can get very loud without distorting. It is super weird how it does NOT turn off when you think it’s off. If it’s plugged in, it’s on, and it will try to pair with something. So if you’re building a custom rig like I am, you’ll want to add an additional power switch.

Bought a few versions of these; work great. Cuts out the static of the junk radio channel ones; cheap and easy to install. I just use a Milwaukee battery pack or wire it into the car harness.

You hardwire power in at 9-24V DC and out to two speakers 100w each, potentially. This will power a variety of 2x ~ 6in speakers out there in the wild just fine. You will need a DC power supply with a fan in it (~200w, ideally 24V > 8A) for a full power sound. POSITIVE: The absolute best feature is the brilliant Bluetooth implementation. No delay, interruptions, warnings, Most, if not all info sounds are short chirps. It fades audio volume for alerts, does not cut out the audio stream. The turn of the volume knob/pot is smooth and dampened nicely a little. Mine unit had a scratchy sound from the pot when adjusting the volume without an input, but was completely silent when audio was playing. The BT antenna is in front next to the volume knob on the PCB. NEGATIVE: Surprisingly the included power cord tail to hook up to your DC supply is very small gauge wire, like 22-24 AWG twisted. C'mon. The wires that power my speakers from this unit are 14 AWG each. Bad place to cheap out on. I'll wire up my own barrel connector, unfortunately. If you're a consumer that knows how you're going to use this, it is great piece of engineering including on the firmware side; you won't be disappointed. If you're the manufacturer, please at least scale up the provided wiring.

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.

Impressive! This thing is great. It's easily powering two 4in subs with two 1.5in tweeters. It also gets very loud, too loud for my liking on the volume control. You turn the knob not even a quarter turn and it's blaring (maybe due to using a 24v power supply). Bluetooth is on all the time if there is power to the board, wish it was off with the power/volume knob. Headphone jack overrides Bluetooth input if you're wandering. Sound is clear, no buzzing or noise from electronics. Wish it had a built-in eq or crossover for the tweeters I'm using but not a big deal. Overall, this is the best micro amp I've bought.

Pierde el bluetooth en cuanto te alejas un poco. Pero es diminuto y funciona bien. Lo tengo conectado a unos altavoces de exterior Bosé y cumple su función perfectamente. Para ser tan barato poco más hay que decir.

Its gud but when u watch video audio speech run slower than video but when u connect with audio cable its work perfect sync audio n video

My house is off grid so this runs from a 12v battery. It drives a pair of old bookshelf speakers. Connects to a mobile phone every time.

Funziona perfettamente, ho riesumato 2 casse Martin da 100 w, piccolo semplice efficace.

Per un circuito cosi piccolo ottima potenza e ricezione