ZK-MT21 Bluetooth Power Amplifier Board 2.1 Channel 50W x 2 + 100W

IT WORKS GREAT! AFTER I PUT IT TOGETHER I WAS TRYING TO CONNECT IT TO BLUETOOTH BUT IT WOULDN'T I THOUGHT T WAS DEFECTIVE OR THEY SENT ME THE WRONG ONE. TURNE OUT IT WAS CONNECTING TO THE NEIGHBORS DEVICE. EVEN THOUGH THIS AMP DOESN'T SAY NLUETOOTH ON IT, IT IS IN FACT 100% BLUETOOTH ENABLED. I'M SO I WAS BUMMED THAT I WAS GOING TO HAVE TO RETURN IT BUT NOW I DON'T HAVE TO. (OPERATOR ERROR) I REALLY LIKE THE ANALOG FEEL OF THE KNOBS, THEY'RE NOT FLOPPY OR LOOSE AND THEY CAN BE DIALED IN NICELY. JUST REMEMBER THERE IS NO POWER CORD INCLUDED WITH THIS AMP, SO MAKE SURE TO BUY ONE. I'M USING A 20V POWER SOURCE TO RUN IT AND IT WORKS JUST FINE. EASY TO BUILD TOO. IT WEIGHS ABOUT AS MUCH AS A PAIR OF EYEGLASSES. I LIKE IT SO FAR & I'M JUST USING IT TO RUN A DUAL SUBWOOFER TO SOME OLD 3-WAY AIWA 250W SHELF SPEAKERS FROM 2001 IN THE GARAGE AND IT SOUNDS GOOD.

I have to rewrite this review because apparently it makes people look bad. I received a used item. I finished the assembly, and am buying a 12V adapter today to see if it works. It looks to be a good item, and while mine was not exactly pristine, it shouldn’t have any issues as it looks by all accounts to be in good working order. If it works, I’ll be updating with a sound test video as I am using it for a custom piece of art that plays music. The unit itself is brilliant in its design and simplicity. The only real issue that I can see going forward is you are going to want to use thinner wire than the heavy gauge stuff that I was going to use originally. A connector might bridge the gap just fine, though. The switch for the on off is tight, and gives a solid click when shut off, not spongy. The other knobs turn smoothly and assembly on this is very simple. Very small screws, so if you have big hands get yourself a magnetized screwdriver so you don’t lose them. Took all of 5 minutes to assemble out of the box, though there was one nut already affixed. It is also labeled 12-24V which means you have some options to power it with and it has a headphone jack to connect it via aux channel. Bluetooth, is the other option which I think might be easier if you are just using it to power some speakers. It is a solid design, and if it works, I hope it holds up for a long time. Good value for the money.

Added some bass to my room I am very pleased, the outer casing is made from metal so it seems pretty durable, it was easy to put together and the Bluetooth was the only thing that worked, the aux port didn’t work. 5 stars very good product

Edit: Despite what the specs say, you CAN NOT power it with 24v. Emailed the seller, they said over voltage protection kicks in over 22. I had a 19v power supply. It did increase the power, but anything over 12v causes background noise. Power it with 12v and it’s a mid-80db amp in my 12x18 cabin that sounds great and it’s $17. DUDE!!!! I’ve owned a Rotel, Harmon Kardon, and used to build award winning car stereos, when it wasn’t just about SPL. I wanted one with the TPA3255 chip, but they were delayed in shipping. I bought this as a stop-gap. DUDE!!! I paired it with Paradigm Micros and a Polk sub box that the amp transformer had shorted out in. It took some playing with it, BUT IT IS AWESOME!!!! First night, I ordered a 24v power source and cancelled my order for the bigger one! I live off-grid, and being able to have a bad ass stereo running straight DC off the batteries was my goal. I can’t even believe it’s a $17 amp board!!! It sounds so good, there are some of my CD’s I won’t listen to on it because it reveals the garbage production quality! It sounds better than the Douk I bought with the 3255, honestly! It’s crazy!!!

This was amazing for the price! Some assembly required but it just worked. This allowed me to run bookshelf speakers on my pc with no issues for under 20 dollars. Sound is good enough for normal day to day use.

The first order, I got, the R channel was just giving out a hissing sound. Had to reorder it and the second unit works great. Fast and easy replacement. So far, a good. Tested the unit with different speakers and make sure you have a good 24v power supply to get the full umphh of the sub.

This thing is horrible! As most digital amps r, but this one goes above and beyond of sounding like a pile! The sub channel is worthless, distortion is a understatement! The main channels are high pass crossed over so won't even make a decent full range 2 channel amp. I am running it at 22v 15 amp power supply btw. It's not even good enough for TV duty. In the garbage it goes. I have the 50×2 and 100×2 which sound decent, more so the 50×2, but this one is a pile! These digital amps really are low quality for audio reproduction, I don't care what anyone says. Nothing beats a class A/B! Which I will b hooking my class A/B 2.1 back up that I also bought on here. It sounds 100× better n will beat on the little 8" passive subwoofer unlike this worthless POS. Save your money, buy a class A/B and an appropriate toridal transformer to run it. I guarantee you it will sound way better and you will b much happier! These digital amps may have their place running 3" full range speakers, but that's about it. I am done with them. Class A/B all the way baby! 🤘

Installed this tiny powerhouse in my Polaris side by side EV UTV using some 3.5 inch coax midwoof tweeters (Orion Cobalt CB35) in the dash above the cup holders whci was the biggest speakers I could fit cleanly with custom 3D printed carbon fiber infused adapter plates. I also installed Rockville VS8K54 8" K5 800W Car Subwoofer under the driver seat (the UTV had been converted to Lithium so that space was empty now, 4 12 volt batteries on that side gone). This combination works awesomely as the adjustments to the sub frequency cross over and volume allows precision matching and provides plenty of power. I am 100% happy with this amazing little amp/bluetooth setup and would highly recommend it for someone trying to put together a decently loud, full range sound that thumps and plays clean on a wide range of music, from deep bass techno through complex melodic vocal instrumental.

Cheap and cheerful, used for a DIY bass shaker system in a flight simulator, and it kicks out some power! Slightly odd app to connect and control, but works fine nonetheless. It's compact and easy to assemble and does the job great!

I used this to power a 35w tactile bass shaker. Haven't used the left and right channels or the Bluetooth function, but it gives plenty of power to the 'subwoofer'. This was so much cheaper than getting a dedicated subwoofer amplifier and does the job perfectly. I'm powering it with a 12v 2amp plug I had lying around and was surprised that it managed to power it given what is written in the instructions.

Did everything I expected it to do. Was a great addition to a Bluetooth speaker.

Excelente producto, supera expectativas por lo que vale, levanta perfectamente dos woofers y un subwoofer de 10 sin subirle a su máxima capacidad.

the aux input wont work if it paired to any bluetooth device so far all i have got is a blue flashing light until paired with something bluetooth but then the aux socket is dead and thats what i need ok with a phone i guess but i dont have a smartphone and never will