MakerHawk 2pcs Bluetooth Audio Receiver Board BT 5.0 Stereo Audio Amplifier 3.7-5V Car Speaker Amplifier for DIY

Very good product as is described by the seller.

Works well, sound is good. Connects to only one device at a time. Passive speaker sound is not that great (depends on the resistance range). Works with old mobile charger (5v). overall very nice.

Voice prompts are so annoying they make my ears bleed. I'll prefer if it connects silently as i can easily see on my phone if it is connected or not

These little things are great! The speed and reliability of the things far exceeded my expectations. Connects instantly, easily identifiable markings on these things. Easily can control the volume with my phone and don’t seem to heat up under normal load. LED indicator is way brighter than it needs to be but not at all a dealbreaker. Very happy with the purchase thus far!

i love things that say what the do and do what they say well. while i cannot attest to it's BT5.0 compatibility, i can say that added to my Denon amp the sound quality is great. i'll add to someone else's comment of, if you're using a phone device, crank the volume up to max and use the amp volume control. i've tried it with an android and an iphone w no clipping. if i get a bit, i'll measure the RMS voltage coming out but i'm fairly sure it's less than the 1.2/1.5v spec and definately less than the 2v/3v max (depends on your reference). i love the fact that it has both 1/8 audio with USB power AND separate solder tabs. seems to be a good quality board with no discernable noise or hiss even with input paused. my only complaint is that you can't change the name. i have two in close proximity and i have to turn one off to make the other one active. having a partial serial as part of the name might help but it could just be seen as clutter. either way i will be getting more to add to my 90 jeep and 92 miata vehicles as well as the back yard. highly recommended.

I wanted something for my classroom audio system, to not fiddle with wires during class. Exactly what I needed for a perfect price. Now I have one at home and at school. The range isn't awesome, if my phone is in my pocket it will start to cut out. But from my laptop, it works great. Sound quality is good! Connects to my devices easily!

This uses a JieLi AS20BP03444-25D4. Don't confuse this with JL Audio. It performs well, however it has a very accented voice notifications that I would love to remove from the programming. I even went so far to look into reprogramming this chip, however it appears to be a write-once-and-done deal. From my research, programming these chips requires specific hardware that will put the chip into programming mode, then the software will upload a key to put it into a writable state, then the custom firmware is uploaded to the chip. This device can be powered by as little as 2.5V, but I would recommend keeping it above 3.2 for it to properly work. Without connection, it only consumed about 7~14 milliamps at 5 volts. A standard voltage lithium cell will power this nicely, but be sure to use a battery regulator board, or this device will overdraw the battery and deplete it. This board does not include any lithium regulation circuitry, and will not charge your battery. It has excellent range, and it remained connected from over 50ft away through interior (hollow) walls. It can be used as a USB sound card if you bridge the pads underneath. No microphone input, but a simple DAC. It showed up in windows as a JeiLi B21 USB sound card (uses standard Windows drivers). It showed as only 16-bit 48kHz. It might not be audiophile quality, but if you need a simple sound card, you're all set!

Received units simply work as they should, no bad surprises despite some negative reviews. Pairs with my iPhone in a snap and stays connected, good audio quality for a basement gym, aux input in an old car, etc.