JUST loud enough to make anyone in the same office ask me to turn down the Judas Priest. It drives some cheap little speakers in a Snap-On toolbox sound bar. I have no clue if the speakers are 4 or 8 ohm or what. Pre-existing circuitry had been introduced to 120VAC through aux input jack by their owner. Notice the little 3.5mm stereo audio input jack? Yeah, perfect for raspberry pi. A generic laptop power supply (NOT DELL or apple.) provides 19vdc to power this little guy. This thing was designed well and built well and it works great...so long as you aren't really expecting more than 5W/ch. That's right...5 (five). NOT 50. Can you honestly complain, for this money? Look at it! Do you really expect some 100W out of it? Ever touch a 100W light bulb? Hey, it works, it was perfect for my needs, it was cheap, I really like it. Yes, there is the occasional hiss noise when powered and not driven. All of our sound needs do not require audiophile-level stuff. All the input/output options and powering options make this thing immediately take care of any generic sound need - without fuss or bother at all.

This review is for the 100W+100W 2 Channel amplifier. This system is basically two complete mono TPA3116 amplifiers on the same board. The two chips are setup at the maximum gain (36db) and this produces a significant hissing noise in my speakers. I replaced the resistors according to the TPA3116 data sheet to produce the minimum gain of 20db. At this level the hissing is completely gone and the amplifier performs excellent!!!!

One thing to note is that the two TPA3116 chips are not synced together, they are both configured as Master and the SYNC leads have no connection on the board so it could not be reconfigured even if you wanted to. I haven't heard one where the channels are synced together so I'm not sure exactly how it would sound they were.

Here's the exact link to the one I purchased:
Yeeco 100W+100W 2 Channel Digital Power Audio Sereo Amplifier Board, DC 12-24V Car Stereo AMP Module for Vehicle Auto Computer Audio System DIY Speakers with Volume Knob Double Chips Heatsink

This is a review for the 2x50w + 100w board. It is excellent, especially for its small size. Almost no noise when nothing is playing. The knobs are all volume knobs. One for the left and right volume, one for the bass volume, and one for overall volume. This allows you to adjust the relative volume of your sub and satellite speakers to correct for different efficiency levels. My only complaint is that it does not reject RF noise very well. I tested this with two Bluetooth boards. Both boards worked fine with another amp, but with this amp one of the Bluetooth boards generated a lot of RF noise and the amp did not reject it. The amp picked up the RF noise even when the BT module was not connected to the inputs. So, it was purely RF noise and not on the signal lines. The other BT board did not generate any RF noise and sounds amazing. My testing was done with 5s lithium ion batteries for the amp at about 18v and an isolated 12v power supply for the BT boards.

Quality Control of this product is horrible. Impossible to terminate the speaker cables because the output terminals were installed backwards. Termination ports are facing the opposite side. Pictures attached.

I have the yeeco 2.1 subwoofer amp in a transperant case.
No power adapter included.
No instructions.
On off switch
12v to 24vdc power input
Running 8 ohm 3 way speakers & a 4 ohm sub
Its plugged into my phone via headphone to rca adapter

I've got this hooked up right now, and first of all, the subwoofer output seems to have less power than the speakers. Could be I'm using a less sensitive 8" sub, and my speakers have old 10" woofers idk.

Next of all, none of the dials are labeled, I had to guess which one is which and the tone controls are weird. It basically has 2 volume dials for the speakers, & 1 for the sub. The sub puts out mid range, instead of a proper sub low pass The binding posts seem a bit flimsy, but they are holding pure copper 16 gauge bare wire ends just fine and the case is fairly thin acrilimide or plexiglass. I'm running it off of a cheap variable voltage power supply set to 24v I also tried other voltages and it worked fine at 15, 20 also

Unit isn't hot or noisy, sounds pretty good, but I'm not getting the isolated bass and tone control I hoped for. Speakers put out static when I run just the sub.

It sounds great with a balanced sound I think the transparent case is cool.

Its pretty loud. Subwoofer is comparatively quiet

The blue power on led would be irritating if you sit close to it, but its good for a living room or whatever.