ZK-TB21 2.1 Channel Bluetooth Amplifier Board, 50W+50W+100W Output, IPEX-1 Antenna Base, 12-24V DC Input, Customizable Bluetooth Name (DAJUNGUO ZK-TB21 Black)

Great amp for my pool speakers. Easy set up.

Review for DAMGOO ZK-TB21 2.1 Channel Bluetooth Amplifier Board: I was happy to see that this amplifier is branded as a DAJUNGUO product. I've played with a range of similar mini-amplifiers, and the DAJUNGUO products do seem to deliver better audio quality than some others I've tried. (Mostly noticeable as smoother high-frequency response.) I do like the way the DAMGOO handles the subwoofer channel: once you set the subwoofer level, it tracks the balance between L/R and Sub as you turn the master L/R volume up or down. For me, this means less fiddling to constantly adjust the subwoofer level when I change listening levels. The bass and treble controls have reasonable hinge points for small top boxes. When initially setting this up, be aware that it is possible to set the crossover point for your sub so low (in frequency) that you may think the sub isn't working at all, or that it's not loud enough. This is more likely to cause confusion if you're using a small sub (8" or smaller), or a subwoofer that doesn't really have extended low frequency response. I'm powering this with a standard laptop power supply: 19.5V at 5 amps. The maximum output power of the amplifier is dependent on power supply voltage and current, so I'm not getting maximum power output from this. The trade-off for me is that laptop power supplies can be reasonably inexpensive, especially if you can source a used one. If you want to maximize the power output, you should probably expect to spend more money on the power supply than this amplifier. With my supply, and reasonably efficient speakers, the amp will play way too loud for typical desktop use, and easily loud enough for most home-theater use. (No, it won't play loud enough to rock the house, shake your window blinds, or throw a house party.) Bluetooth works well once enabled. I had no problems pairing, and a range of 50 feet was workable in open space with no obstructions. Like all of the low-cost mini-amps I've tried, switching between bluetooth and wired inputs sources is kind of frustrating, and is accompanied by changes of level and notification sounds that are too loud. Since the issue is so common, it's best to just learn to accept it and adjust to it, if low cost is important to you. (To be fair, a number of far more expensive mini-amps I've tried have the exact same issue with source switching.) The amp is tiny, and won't take much in the way of desk area-- the power supply you choose will probably be close to the same size as the amp. Like most budget mini-amps, this one is not completely enclosed in a case: the sides and rear are open and exposed, so pick your location to protect it from spills, debris, or children poking things into the side of the housing. At the time of this review, the cost is $18.98: audio quality and 'fun' are astonishingly low priced.

Wow! Sound quality was perfect

Amp stopped working the day it arrived

This saved my 20-year-old Klipsch 2.0 speakers. The internal board gave out, and I was able to run everything back through this amp board and give new life to my favorite PC speakers.

Great to be able to have such a small amp with so many features be able to power some bookshelf speakers so easily. Simple setup and very good sound. Fir the money it's a great deal if it's what you're looking for. Seems decent quality and the connection over BT worked well for us.

A small compact 2.1 channel bluetooth amplifier ready to integrate into an audio DIY build. With up to 50W+50W+100W output and an IPEX-1 antenna base, you can construct a portable speaker system with bluetooth connectivity. The output power depends on the speaker impedance (2-, 4- or 8-Ohms coupled with a range of input voltages ranging from 12VDC to 24VDC. There is a 1st gen IPEX interface that can be connected to a U.FL/IPEX 2.4G antenna and adapter cord (neither supplied). These antennas are mostly sold in pairs but I did find several single antennas at Amazon. Source input an be via BT or analog via an AUX jack. One bummer was that they show an IPEX antenna on the description page but an antenna was not included. They should update the page to clearly state the antennal is not included. It is obvious elsewhere in the text it's not included but that picture implies that it is. The controls operate smoothly and you can control combine L & R bass and treble and sub-woofer cut-over frequency and volume. It is a cure little thing, not a Cadillac-product, but then it only costs $19 and sufficient for an inexpensive DIY audio project.

This little Bluetooth amp works decently for what it is. I used it for a diy speaker box project and it works as it should. Bluetooth connectivity is easy to set up and you can go a good distance without it disconnecting and getting choppy. You get a decent amount of volume and sound for the size of the unit. It's easy to power with a 12 volt wall plug or with a 12 volt battery. The tuning could be much better, but for the price of this thing, I can't really complain about sound quality because it would be ridiculous to think that you would get the best sound from something like this. I have it powering 2 regular 6.5 car speakers and 2 8" subwoofers. Again, for the price it's pretty decent and it works.

Buen producto. Me llego bien y es tal como lo anuncia.