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.

This little thing is awsome!!!! I run it off a 20v drill battery on a speaker box with 2 car 6x9 speakers. Its clear sounding and loud with plenty of power for good bass. The bluetooth works great on it and runs for hours on one 20v 3amp hour battery. I was very impressed by this well worth it and cheap.

Like it overall. Didn't try the Bluetooth connectivity. Not super powerful, but good for low power projects.

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 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.

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

Worked perfectly for about a week. I never ran it hard, but only at maybe up to about 70% volume for a few minutes, and maybe 40% for the rest of the time with a couple 20 watt speakers and a 40 watt subwoofer. Then, without obvious cause, it started to have horrible static on the bluetooth. I tried power cycling it, removing power, reattaching power, reconnecting bluetooth, etc. Nothing helped. Fortunately it's within the return window, so I'll return it and try another of the numerous similar options.

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!

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

nice little amp, easy to wire up i have mine running from a 13.8 v CB PSU at 6 Amps sounds great no hum but i am using high quality cables for input, not using the sub channel as my 8 inch sub is active, easy to assemble the case, although quite fiddly (tiny screws) Definitely Recommended. Not tried the Bluetooth but no setup instruction for that.

Good

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.