LiNKFORHiFi Headphone Amplifier with Bluetooth 5.0 Receiver 16-300Ω Earphone Amplifier with Gain Switch 3.5mm Aux with 40 inch Audio Cable for MP3 MP4 Laptop

Bought as a bit of a workaround to deal with a phone with a really quiet headphone output. You can barely make out what is being said on spoken word audio like podcasts or audiobooks.So, add in this amplifier and it is as loud as you could ever need it to be - either via Bluetooth or headphone jack connection. Bit of a bulky solution but problem solved!A major issue here is that the Bluetooth leaves much to be desired. It connects easily enough, and I'm using it within a foot of the phone so issues are minimal.However move more than 3 ft away and the signal begins to break up. Even a human being passing between the source and the amplifier is enough blockage to break up the signal. It really is feeble! If you need this amplifier to Bluetooth connect to anything that doesn't share the same table (or coat pocket!), this is not the device you want.

I am demoting this to one star because it has now failed completely and I had no reply from the manufacturer.This device provided the "oomph" for my big Philips headphones that my Motorola phone couldn't supply - as well as breathing amazing new life into smaller, cheaper earphones.It also added Bluetooth capability to my wired earphones.It had decent battery life though I use it 12 hours a day so it needs charging at night.The volume control knob was also welcome - but this is its downfall.The volume control got a bit "scratchy", and now the physical power switch (no bad thing in itself as it stops the battery draining on standby) has become intermittent so the unit keeps rebooting - which is annoying in itself because it takes a second or two, but especially since some media players either stop or default back to the built-in speaker.

...I had to return mine as I found the Bluetooth receiver to be unusable, cutting out frequently. I have many Bluetooth headphones and modules and none of these have this issue.What I found was, that the Bluetooth antenna is located at the rear of the module in what appears to be a semi-transparent PCB or non-metallic part of the unit, when directed at your transmitter, be it your phone (in your pocket, bag or other unit located somewhere), the issue disappears.Again, I do not have this issue with several other Bluetooth modules so, I returned it.What I do hope, however, is that it was merely a fault with the unit, and WILL be purchasing this again once my refund is complete.It seems like a genuinely lovely product in all aspects, so I hope the next one received will not have this issue – I will update this review after such a time…

great product easy to install, would recommend the only negative would like it to be a bit louder.

I got 2 of these things they're just that awesome. Honestly this is such an awesome purchase. Boosts sound like crazy, decent quality for such a low price. Highly recommend.

Purchased this as the sound from my laptop is not very loud, this does the job very well and improves the quality, I all have used it on my iPhone, iPad and iPod Touch.I have knocked two stars off because the output sockets are of poor quality, they appear to be very flimsy and I think with constantly plugging and unplugging they will fail so I leave an adapter plugged in, also occasionally I have had to twiddle the plug to get both stereo channels to work, but considering it was only £32.99 it’s not bad value and does what I purchased it for.

An improvement on typical direct sound from phone or tablet (primarily better control over volume). Bass boost is either on or off. Build quality solid enough but has some extremely sharp edges where the aluminium shell material was cut - I suggest rubbing edges down with a little Emery paper to avoid unintentional bleeding from fingers or holes in pockets.

I haven't used this as a headphone amp as such but it really does amplify the aux in signal for my car stereo significantly. Going direct from my iPhone 3.5mm jack out, the sound was weedy, but this little box has really beefed it up. The bluetooth connection has been solid so far with no dropouts; I can't really speak to the range as it's not been tested beyond approximately one metre. The sound quality seems very good too. The build quality leaves a little to be desired - the high/low gain switch has too much play and isn't as stiff as it could be, but this hasn't led to any functional impairment in the sense of actually switching when it's not supposed to.