M15i Headphone Amplifier Portable DAC USB DAC Amp with Dual-Jack, Portable Headphone Amp - Apple MFi Certified, Hi-Res DAC - Low Noise, for iOS/Android/PC

Some of the reviewers just don't know what they're talking about, which is typical of bad reviews written by people who have no idea what this is for. First, this is an outstanding DAC/amp that sounds better than any built-in sound card. It does need an OTG USB-C cable to work and it works beautifully with all Apple products as long as you have an OTG cable. The iPhone 15 Pro outputs more power than previous iPhones that had lightning ports, so just be aware of the limitation when using older iPhones. The supplied OTG cables work but they aren't the best that are available (typical of all the competition) and there are better OTG cables available.The sound quality is great - this is comparable to or better than any competing product up to $400. It draws less battery power than almost all the competition because of the unique Questyle amp design. It does not have ridiculous EQ settings or volume settings, which are best handled at the source via software and hardware controls before the signal gets to the M15i. The only setting on the unit is for regular or high output, to match with efficient IEMs or regular headphones that need more power. The 4.4mm balanced output is more powerful than the 3.5mm unbalanced output, which is to be expected. This can drive any of my headphones and IEMS, going up to my Focal Clear and an Audeze MM-500.

First off like so many other videos that I reference there are many videos about this product go look at one of them they're all over YouTube. But I will tell you this this product is fantastic it doesn't drain the battery too much. It produces exactly what it's advertised to do it makes music sound fantastic on your phone or in your car. Now on a side note I do not know if this is an Android issue or a Samsung issue, but the one buyer beware note I want to stress to people is the volume output of the device does depend on what device it's being hooked up to. For some reason just like other dongles that I have bought when paired with the Samsung phone the volume output is not as strong as when paired with other phones particularly other Android phones. So I think this issue is more of a Samsung thing. Other than that pay this with anyone of great iems or true HiFi headphones and you will be amazed

This DAC Amp doesn't have many features, but it does have the most important attribute of all: It sounds absolutely sublime.Highly recommended.

For IEMs, it's not a real improvement to the Apple dongle. Quite pricy.