Headphone Amplifier with Bass Boost, Support 3.5mm AUX and Type-C 16-600Ω Headphone -3.5mm Stereo Audio Out, GAIN, Bass for Mac, Phones, iPad, MP3, MP4 and Computers,Xbox one,PS4,PS5 Controller

What's up with cell phone manufacturers removing the headphone jack, right?The paranoid among us know using Bluetooth is a potential security risk. The Audiophiles among us know there are limitations in the on-board analog audio and Bluetooth digital stream. Although this device does not have the quality of a several hundred euro/dollar DAC, it is good. I use it though AKG open back headphones,Bose closed-back earphones, and Sennheiser earbuds. It sounds good.First the audio: It works well with the USB input source. It worked with my Samsung phones and tablets. No hesitation, it was just like plugging in a headphone right into a jack. Worked just as well on my Windows desktop.In-line with the audio out (headphone) jack on the desktop and my tablet worked just as well. A definite improvement over simply plugging the headphones straight-in; more mid-range and base, a deeper sound stage, but maybe some narrowing. You can get even more bass with the enhanced bass equalizer setting. I can't say how long the battery lasts, though (more on that later).All in all, it is quite a functional DAC/adapter, no significant sound color, no static, hiss, or added noise. It is not as good as my desktop audio interface, but it's 5% of the price!Construction: Nice brushed and anodized aluminum case, Feels sturdy; if a bit heavy.Controls: Volume knob is silky; with a definite audible 'click' when you turn it on or off. On the 'front' with the volume control knob, there is a bass boost equalizer. On the back is an switch for high impedance headphones. You'll know if you're using high impedance headphones, and it's nice to have that feature. I found the slide switch on the back to be a little awkward, but you don't change it much unless you're changing headphones. The bass boos and impedance switch are tiny and a little award to use.BUT, be careful of running the battery all the way down. I may have left the unit on and completely drained the batter. Trying to use it from the totally discharged state was as if it stopped working. It wouldn't show the blinking charge light after totally exhausting the battery. Neither in-line or USB modes produced sound. Fortunately this was, within the warranted period. Amazon is replacied it with the same device. Did running the battery down damage it? Is it so heavy that it broke a conductor in the USB connector? Was it simply a production mortality issue? I have no idea why.I would still recommend the device. But I'd also recommend you seriously use the device during the initial 90 days to make sure it will provide you with a quality alternative to the missing headphone jack.

UPDATE: Somehow the right channel has stopped working, but only when used with USB-C input. Analog is still fine. Tried multiple devices to no avail, don't even know how this is possible.Summary:Very nice overall. Happy with my purchase. A few minor qualms, but overall exactly what I wanted. If you are trying to decide between this unit and the cheaper ones that are analog-only (specifically the million other visually identical ones that say not to use them while charging), you should absolutely get this one. It's just a way better, more flexible design. Worth the extra money by a long shot, though the build quality leaves something to be desired, costing one star. Despite this, it's an excellent piece of ChiFi gear, and likely the best headphone amp I'll ever need.First impressions:Used with Sony MDR7506, so this may not be the best benchmark for raw power. It sounds pleasant, has tremendous headroom, and the bass boost is a little excessive but not awful. The unit has a very nice weight to it, feels very solid. Nice relay clunk when you turn the unit on, and being able to accept both analog audio and digital audio is what sold me. USB works out of the box on Linux with built-in USB audio module, not sure about Windows. Not a big fan of the brushed aluminum case, but that's just personal taste. Would prefer a matte finish. Tolerances on casing are a little wonky, but not bad. Some light bleed around edges etc, but for the price, that's fine. I'm less fine with the hideous, excessively bright, blue LED. I wish they would stop using these. Also would prefer the USB-C jack to be on top so the port/cable isn't as stressed when in a pocket, but there's not a ton of space up there, so I see why they put it where it is. Could also live without the printing on the front and back of the unit, always thought this looked tacky (in the same way chromed plastic did in the mid-2000's), would be better suited to the bottom near the USB-C jack.Internals:Didn't see any reviews talking about this, so I took a gamble with mine, but it paid off. Very competent design with decent component selection, only minor issues regarding longevity. First thing you see when you open the case is a very large LiPo battery with built-in protection, which takes up most of the inside of the unit. Unfortunately it's soldered in. Despite being surface mounted, the pads are reasonably far apart, so it may not be a *huge* nightmare to replace. May cut the wires and attach a JST connector if it makes it that long. My biggest concern is dubious soldering on the audio jacks, they're surface mount and there is so little solder on them that you can see the legs of the jack on the pads. They might break off in the unit if any force is applied. I preemptively shimmed mine with electrical tape to hold them in place because I'm somewhat rough on equipment. Panel mount and/or through-hole jacks would be nice for a future revision, and I will likely replace mine with these should one break. On the other hand, the USB-C connector seems reasonably solid/well attached. Additionally the switches, despite having a fairly fragile-feeling actuator, are through-hole and seem unlikely to break free. There's also an interesting potential for modification given some of the quirks of the device. It has what seems to be exposed I2C pads on the board, attached to an M0 microcontroller. Not positive, but I think the microcontroller sets up the codec and configures it to mix the analog input into the output since the codec doesn't seem to be designed for this usage. The codec itself has some compelling features, could possibly be modified to support in-line controls, mic input, as well as S/PDIF output, though this may be hampered by the onboard OTP flash. On the downside, the OpAmps are probably counterfeit/factory rejects, they look dubious, and the markings don't look like typical TI parts at all. Sound fine and seem to work well enough that *I* can't tell, so maybe not as bad as you would expect, but still worth noting.The major components are as follows (for the nerds):IP5306 - Battery Management (Power Bank on a Chip)TPS65130 - Split-Rail DC-DC Converter for OpAmpsCM6642 - Codec with 24-bit/192KHz In/Out25VQ80ASIG - 8Mbit FlashMacrosilicon MS8006 - M0 MicrocontrollerA few NE5532's - Likely for the bass boost function and active volume/gain control, not sure.Edit: Something worth noting, this does not seem to be a USB-C dual-role device. I couldn't get it to behave in USB device mode when connected straight to an Android phone with a C-C cable. It would only work through a USB-C to A adapter, then a USB-A to C cable chained into it. If I didn't do this, the phone simply wouldn't detect it.

I recently changed from a FiiO A1 to this unit and I am impressed.The A1 is smaller and lighter. But it is dominated on every other dimension by this unit. This piece costs less, is more powerful, has a longer lasting battery, uses a USB-C cable for charging (the same as my phone). It's slightly larger size and weight are not problematic. I like the knob for on/off & volume control better than the buttons on the A1. I used the A1 for around 5 years, I hope this device lasts a similar period of time.The sound production has been the best improvement. I am running a Sony Walkman NWZ-A17 high-definition player. I play music, mostly symphonies and classic rock, in FLAC CD-quality tracks. My headphones are either a set of Sony cans or Audio-Technica ATH-ANC9 noise cancelling headphones (when traveling). The sound is clearly richer, more detailed, and warm. A far superior listening experience. Well done.

I drive a 2008 Toyota avalon and it definitely needed the bass boost. Really helps especially since it connects to aux instead of a crummy Bluetooth-aux thing. It's easy to use and adjust and not bulky. :) just becuaseful when connecting it cuz I broke the first one jamming the aux cord into it often. Holds a charge really well.