ZK-AS21 TPA3255 Bluetooth 5.1 Power Amplifier Board HiFi 2.1 Channel 220Wx2+350W Digital Audio Receiver AMP Board with Treble and Bass Control for DIY Speakers

Amazing, powerful little amplifier. The app isn't the best, but considering it's $30, it's pretty good. It's able to power a subwoofer, 2 tweeters, and 2 midranges with no problem. Its built in cooling fan keeps it ice cold, so there's no need to worry about overheating. Its size is also very compact, making it easy to take with you. Its bluetooth is amazing, with absolutely zero noise whatsoever, compared to its little brother ZK-MT21. Now, onto the CONS: 1. For some reason, the AUX input is delayed, and it's obvious when you try to play it with other speakers. 2. The main volume control isn't measurable, as it's built for the app, so you have to eyeball it when setting the volume (it never stops spinning). 3. From its size and power, it requires an external power supply. I used a 36v 10a power supply, which is PLENTY for it. 4. Since the terminals are so close together, be sure to turn off power before adding speakers to prevent shorts, and make sure there aren't any loose strands.

I'm more impressed with this one over the larger 36v $36 one of a different brand I was using that cooling fan crapped out. This one sounds better more dynamic and seems to have as much power at 24v also I had to unplug the 3.5mm jack to use the Bluetooth this one you can just link to it even while using the jack as input and it was half the price and no fan to crap out. I'm using for my tv I boxed in the stud cavity's in the wall under my tv and cut in a 6.5" component set and an 8" subwoofer, it's pretty sweet, I also used PVC pipe to install a port into the subwoofer cavity I had to replace the sheetrock with plywood and mud it in like drywall also the sheetrock couldn't support the pressure good even with a wood ring glued on.

I’ve got this powered by two Makita 18v batteries equaling 36v. I connected two Boss 6x9” coaxial speakers that are 4ohm each and a Skar 8” subwoofer that is 2ohm. I must say this amp is awesome! I ran it for 5 hours bumping hard in my shop that was 60 degrees and it didn’t even get warm. My shop was rattling. I ran it through a bass sweep and it does 30 to 50hz very good. It only used one bar on the battery indicator so I’d say it works well and is not a knock off. It connects to Bluetooth easily and reconnects if I go out and then back in which is a big deal to me. The connection voice is English and is pleasant. Definitely worth it.

Works is great for my simple PC audio setup. No noise or anything via AUX or Bluetooth.

I have a couple of these. Bluetooth sounds better than using the cord. Use an appropriately powerful DC laptop brick or anything similar if you want the biggest sound. The one connected to my PC uses a 200w 20v DC brick to drive 4 speakers (2L and 2R in parallel) plus 2x 12in subs (also in parallel). It will shake things off the walls in my house. You won't believe the performance from such a cheap device. Pros: Easy to assemble, wire, and connect power. Bluetooth setup is simple. With the right power and speakers/sub, your neighbors will think there's an earthquake. Cons: Slight hiss if you leave the main volume knob turned up to max with nothing playing. If you're listening to something with pauses at low volume, it may not play the next spoken syllable or noise. This does not happen at medium volume or if the movie you are watching has birds chirping etc in the background. It's almost as if it goes to sleep for a fraction of a second.

I'm seriously impressed with the sound quality this amp produces. I purchased the zt21 about a month prior to this one. But the zt21 kept popping while playing music. Thought it was capacitor so swapped it out but still the same issue. Then I noticed if I blew on the heat sink when it started to pop, it would stop. Placing a fan on top solved the problem. So that's why I chose the HT21, because of the built in fan, but was surprised at how much cleaner it sounds. And the knobs to control the Frequency, Bass, Treble, and Volume are much more accurate & smoother than the zt21. Bluetooth sound quality is significantly better as well. I use a 24V 5A LED Driver power supply for good clean power, but I also use ~ 30V high amp 18650 lithium battery packs I make, when I want my system to be portable. Overall, this is a much better amp than the zt21, it may be more expensive, but well worth the price. Just remember to use a good quality power supply or battery pack for a nice clean sound. This one can take up to 36V/ ~10-12 Amps I believe.

Ficou mais barato montar o som.

Best product 👍👍👍👍👍👍👍👍👍

Tiene. Un buen sonido. De calidad. En un dispositivo pequeño. Ay. Un gran. Equipo de audio execelente

This is one of the best 2.1 channel amp. I had oneplus q2 pro 65 inch tv and the tv stopped working after a year but the tv had best sound system ever,i never saw a tv with such sound system. So basically i wanted to reuse that sound system with my new lg c4 so i took out the speakers subwoofer and the tweeters from oneplus tv but the sound system was passive and needed an external amp to drive them. I ordered couple of amps before but they were giving good sound quality. Finally i ordered this amp with seperate channel for subwoofer and it works amazing. For now I’m using it via Bluetooth and the sound quality + bass levels from subwoofer are 8.5/10. I imagine how good the quality will be via wired connection,so i have ordered DAC,digital optical audio cable,aux and i know it will sound much better via wired connection. I have checked all the 2.1 amps on amazon some good brands are above 8k and the ones under 8k aren’t good. Don’t judge this amp considering its cheap price,just buy right away. Only thing i am concerned about is its logetivity since it has no warranty. Rest i can assure you that its the best amp.

Best