HiFiMAN Express HM-101 Portable USB DAC

Chipset: 16-bit, 48 kHz Texas Instrument PCM2702
Frequency Response: 20 to 20k Hz
THD: 0.07%
S/N: 96 dB
Stereo Crosstalk: 78 dB
Output Level: 1.5v at 36Ω ; 2.0v at 150Ω
Max Output: 62mw at 36Ω ; 26mw at 150Ω
Dimension: 36 * 60.5 * 13.8 mm
DAC: Burr-Brown PCM2702E
AMP: NXP Semiconductors TDA1308 integrated class-AB stereo headphone driver
Compatibility: Windows, Mac, Ubuntu

Package Contents
- HiFiMAN HM-101 Portable USB DAC
- USB Cable
- Manual 

"This little box transforms any computer to a great sounding juke box. Usually I can't stand the sound of any computer's standard output. Hell, with my UE Trifi 10's most computers don't even have the output necessary to drive them. I HAVE to use an amp. With this little guy that slight inconvenience is gone.

It doesn't sound as good as my 24bit/192khz Fiio. But for it's size/weight/cost I LOVE IT. It's output of 16/44.1khz is far greater than straight out. This has the very nice Burr-Brown pcm2702 chip in it. It is found in many top-end receivers and DAC's

Get it, It will make your headphones happy!"

Quoted from Amazon.com user review by CharlesT 

"First thing I noticed was the nice glossy finish the HM-101 and the brushed aluminum finish on the housing which was a big surprise to me as I thought the product's housing had a plastic housing from the pictures I saw on head-direct. Great build quality. Plugged the DAC into my computer and Windows automatically installed the drivers so the product was good to go, no need to manually install anything which is very convenient.
...
One of the things I easily heard that was different compared to my Auzen Prelude was how lush the mids and highs became from what I was previously used to. Lots of smaller detail I didn't notice before and vocals stood out a lot more. It was a completely new sensation to my ears. I tried out a few of my other headphones to do comparisons with my soundcard and the DAC just to make sure there was a noticeable difference." 

Quoted from Head-fi.org forum user review by EpicPie

"Sound itself was good. Detail came across well, I had good crisp highs, good mids, clarity, and the overall signature was warmer than some other sources I've compared to. I wouldn't call it special compared to things that cost equivalent or higher than it though. It's not better than a typical sound card. But it is better than a bad quality onboard sound option. Note, some onboard options are actually really good and superior to this unit. I think the highs are a little bright, I noticed some of my headphones gained some edge to them that was not previously there.

The amp side can push headphones quite nicely. It won't take care of maximum impedance inefficient insensitive headphones. But it will power most headphones without much effort."

Quoted from Head-fi.org forum user review by MalVeauX

"The sound was remarkably analog, and it reminds me a lot of the sound of the HRT Music Streamer DACs. And due to the analog sound signature, I really don’t mind the high noise and grain levels, as it goes really well in the overall presentation, sort of how grain always romanticize film-based photographs, or how pops and noises are an accepted part of the whole vinyl listening experience. The warm and mid-centric tonality is very likable. Not only because it’s warm and mid-centric, but also because you never get a feeling that things are dark and muffled, thanks to the superb, spacious depth of the soundstage giving a very good image of the venue where the recording was taken.

I have no complain with the treble as it was clear enough and wasn’t wrong or bothersome to my ears."

Quoted from Headfonia.com review by Mike

"Using the headphone out jack on the HM-101 adds the much needed oomph in the sound, making it more musical and lifelike. Bass can be low when it needs to be, mids flow with presence and liquidity, and treble is not choked or rolled-off. Though not a tenfold increase in volume compared to the line out jack, this is more of a twofold one. And that is more than enough for most genres of music, even for online videos that play weak even when turned all the way up."

Quoted from Headfonics.com review by Zaafiel