TUNAI Tunai Square Bluetooth Headphone Adapter - aptX & aptx Low Latency Headphone Amp Makes Any Headphone Wireless - Portable Bluetooth 5 Receiver - Low Noise DAC - 7hr Continuous Playback

I needed these for a project that required essentially synchronized sound in two locations where it was not feasible to run wires. Pairing was easy, use was straightforward. The audio quality was sufficient. I didn't measure the frequency response or noise, but I had them connected to large powered speakers - there was no noticeable additional hiss and they sounded good. My source material wasn't great, but I didn't notice any obvious degradation. The entire system worked very well from barely audible to danceable with all of the volume control being done at the source with the monitors and bluetooth modules left at full volume. The only issue I ran into was that they timed out after some number of hours, but that was easy enough to recover from, and would not be an issue for most users.I normally use EarStudio ES100s for this application, but they don't support aptX LL, so they don't work very well when you can hear both sets of speakers at the same time.I was a bit nervous buying two of them without any reviews anywhere on the internet, but they definitely sound better than the $30 adapters I've used in the past and I didn't run into any issues. The only hokey thing about them was that initially, I couldn't tell where the power button was as it doesn't have a tactile switch so I didn't get any immediate feedback when I pressed it.

It's a solid adapter for anybody who is looking for a more wireless approach to listening to audio on the go, and it is particularly useful for users who own a phone without a headphone jack and dongle.Just make sure your device is BT 5.0 compatible, and you can get pretty decent range on these if you ever leave your phone anywhere if you're walking around the house with them on.Now to my review, and I can say a lot of good things about these. They're lightweight, and also drives my higher end headphones and IEMs without a sweat. It's easy to operate and use, and you can feel where the buttons are thanks to the bumped legends on the adapter.Battery life over a year is kind of iffy at most, but it looks like it is replaceable as I opened up the unit accidentally and got a glimpse at what the PCB and the battery looks like.Overall, it's a pretty good adapter for the price. It's a tad bit expensive for what you're getting, but compared to the other higher end options, this is a pretty good buy. I don't regret getting these.

First, the sound quality is great. Not Excellent, but very close. Gets plenty loud and the onboard amp while strong, easily strong enough to power 100 ohm headphones might not be able to hang with much more than that. IEM's are powered easily, even those with multiple drivers. I have KZ AS10's, ZX10 pros both Hybrid 5 driver per ear and are powered thoroughly. Clean as well, though it could use a little more head room in high gain low amplification situations, usually caused by my switching off volume matching. My suggestion is to set Max on the receiver and control volume using your mobile device or sources volume control. Soundstages, if your headphone produce good wide stages, will be even wider with acute separation. Excellent. The amp does not color anything as it is clean power. But as I said, too much gain will produce low volume hiss and hum if the gain isn't used conservatively.Battery life is average with hybrid IEM's. Lasting about 5 hours continuously at high but not Max volume. Max volume is way too loud for listening without damaging your hearing. But even at that volume, everything is clear and undistorted. At most people's normal listening volumes you could reasonably get 8 hrs. It also depends on what you're driving. With hybrid IEMs, while not like power hungry cans, still use up much more juice than your typical single driver earphones, cans or in ear.Price, for what you get, is a steal. Buy this. You won't be disappointed.

This worked about 5 times and then while using it at the gym, the volume suddenly went to max. It was so loud I was afraid that it had damaged my ear drums. I turned it off and could never turn it on again. I charged it and all but it is dead. Absolute rubbish.

I'm very happy with this purchase. Things I like about this device:1. Cable management is very useful.2. It's light and compact.3. Great audio quality. No audible hiss even with sensetive IEMs (which is a problem with most of BT receives). Gets loud even with relatively non-sensetive headphones (Pinnacle P1).4. Power button is instant. Most other BT devices require to hold a button to turn on/off, which can be annoying. It's not a problem with this device. Put the button, it turns on. Push it again it turns off. Both with a quick voice feedback.