Bought to replace an older, cheaper DAC/AMP I'd gotten for around $40. The K11 works wonderfully for all the headphones I've got (Takstar Pro 82, Hifiman HE4xx, Phillips SHP 9500S mainly), and has a wide array of features as well. Getting to updating the firmware is a must however, as there are some quirks that the K11 has on its stock firmware that disrupt the listening experience. Thankfully firmware updates aren't terribly painful, though it took some digging to find proper instructions. Once that was settled, it worked beautifully though! Great looking, well functioning buy for those who are looking around this price point.

Generally great sounding and a solid performer in a neat package. I would recommend this unit, my only complaints are minor nitpicks.Pressing in the knob for 5 seconds to turn the unit off is a pretty annoying design choice for something you will likely want to do every time you use the unit. I have read some reviews that seem to think turning off the unit is impossible - this isn't true, but it highlights the poor design choice.It also seems to take longer than necessary to boot up. This hasn't been my experience with previous headphone amps at a similar price point.. Is it because I need to have ~7 seconds to have time to read "FIIO K11" on the display?The volume knob can only select at increments of 1, so if you want to make a large adjustment to the volume, ... MoreGenerally great sounding and a solid performer in a neat package. I would recommend this unit, my only complaints are minor nitpicks.Pressing in the knob for 5 seconds to turn the unit off is a pretty annoying design choice for something you will likely want to do every time you use the unit. I have read some reviews that seem to think turning off the unit is impossible - this isn't true, but it highlights the poor design choice.It also seems to take longer than necessary to boot up. This hasn't been my experience with previous headphone amps at a similar price point.. Is it because I need to have ~7 seconds to have time to read "FIIO K11" on the display?The volume knob can only select at increments of 1, so if you want to make a large adjustment to the volume, you will be making multiple full rotations of the volume knob - not very satisfying.You will probably want to change the RGB settings the first time you set it up, as the default is fairly garish (you can turn them completely off if you like, or just use solid white).This isn't a negative, but don't forget to go and select the GAIN setting to suit your setup. The default was not appropriate for me.

So far I was more into using some high-end mobile devices for listening music and This is my first time I thought to use a dedicated DAC/AMP for headphones. To my surprise this little wonder from Fiio have performed beyond my expectations. It has kickass soundstage, excellent flat response and mind blowing power. Wish it had auto power down feature when not in use. But other than that K11 works flawless for your needs.