ZK-TB21 Bluetooth 5.0 50W+50W+100W 2.1 Channel Subwoofer Amplifier Board TPA3116D2 HiFi Treble and Bass Control Stereo Digital Audio Amp Board for Home Theater DIY Speakers

I am an avid audio addict. I have a massive collection of audio gear from high end vintage stuff like luxman, b&k, marantz, hk and many more as well as 20+ pairs of great speakers, mostly vintage "Heritage" Klipsch. I bought one of these on a whim because I wanted to out some speakers and small subwoofer I to one of my old cars but I wanted to keep the factory stereo head unit in it for the look and hide a small Bluetooth, 12v amp in the glove box. I hooked this up to 2 blaupunkt 6x9's and a 6.5 inch Boston subwoofer and holy crap it sounds fantastic! I have several vintage vehicles and I will be ordering 10 more of these to keep for future conversions. It punches way above its weight class, sounds clean, and clear. I highly recommend!

Design quality is surprisingly decent. It is not fully enclosed and the sides of the box are open just like the pictures, but the PCB, solder quality, silk screen, etc are all pretty good. Components are obviously not name-brand, but off-brand resistors/capacitors/etc are OK now days it seems like (not sure about long-life though). Bluetooth connection range is OK, reaches through 2 walls in a house at least, but there was a random clicking noise in the bluetooth audio mode even when up close. That's fine for me since I'll be using the 3.5mm jack which doesn't seem to have any audio distortion that my ears can pick up. But I'd be cautions buying this if you plan to use it and use the bluetooth. Power output seems sufficient. They always lie about the "max output" on pretty much all audio equipment, but the same is true for speaker input wattage. I'm running this with about "2x40w rms" car speakers on each channel, 4 total speakers, and it is more than loud enough without clipping, powered through a 20a relay the car battery 13.5v source.

I'm not going to lie, I thought this was going to absolutely horrible but I was blown away. I ended up 3D printing a case for this if that helps to express how impressed I was. Granted, this feels cheap. The nobs are meh, the DC port sparks when you plug it in, and the wires are completely exposed, but dang it sounds nice! Its crazy. The sound fills every corner of my apartment. My wife was even impressed with this odd effect, she'd walk into various rooms and come out saying "the audio hardly changed wtf!?" I guess she likes it. I replaced the stock speakers in my car and used this to recycle the old car speakers into a makeshift boombox out of cardboard. I actually started laughing at how good the audio was for this type of setup, I still laugh about it when I turn it on. I sits on my workbench and my friends see it and instantly have questions. I turn it on and we all have a laugh, its fun really.

using for a van office build ... 2.1 computer setup this thing blasts loud and clean on house battery bank: 13V takes only 0.25 Amps at 75% volume. Definitely more sound than my ears can handle. CON: no Aux filter .. laptop is giving out noisy signal, this thing has NO signal cleaning (for ex: prior Logitech 2.1 setups clean Aux incoming audio nicely) .. so only works well over bluetooth .. so pray the connection is stable.

I got this ZK-TB21 for just under $20. It's wild something so cheap sounds this good. I hooked it up to some older NHT speakers (A450 bookshelf pair and SW2Si subwoofer) and it's great. Don't expect it to match $5,000+ tier amplifiers, but as long as you get some good speakers, it will treat you well.

Excelente producto.

My buddy gave me some brand new sonance outdoor speakers. I was going to use them indoor as presence speakers but noticed the output and ohm rating were different than my receiver. I decided for $0.18 I couldn’t go wrong. (Used my Amazon points). Anyways, I was shocked after I assembled and wired this amp board up. The speakers sound perfect with no harshness or dropping out. I opted to go with a 24v 6ah power supply to get the full potential. My buddy who gave them to me was shocked by the clarity and the sound the little board produces. It syncs up immediately with the Bluetooth on my iPhone so I’m able to play Pandora outside with crisp clear sound. Can’t wait to buy the buriable bass channel. If it delivers the way the other two channels do then my bass will be digging deep outside too.

Bought for thmy Bluetooth mode and it’s not worth it. It won’t connect to anything but the phone

Ficou mais barato montar o som.

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.

Power full module sound quality ultimate effective equal 5.1 module

More than expections received original ic bord thank you amazon.

Good sound quality