Summary: OK, but just not quite there yet. It's a bit sloppy, loses composure with more complex material. Bass seems a little thin. Headphone amp needs more power and a cleaner sound. It's an improvement over a p/c sound card for sure, but not compared to some other products in a similar price range, or for not much more.
Pros: Convenient, easy to set-up and play, no drivers, well built
Summary: Great product. I bought it because my headphone port on my Macbook pro has some issues and wanted something to bypass it. This was absolutely the best remedy. The DAC is solidly made and the packaging is superior to most others. The sound quality is quite exceptional with good headphone/speakers. I would 100% recommend buying this!
Pros: Good sound, build quality, packaging
Cons: Maybe the price is bit high? I don't really care the DAC is too good.
Summary: Was very skeptical about this product but installed it on my iMac. Made a world of difference over the standard mic port. Amplifier is clean with no hum. Cleaned up the bass but especially the mid range. A little bit of a 3D quality.
Summary: The Audioengine D1 has great design and build quality, and the audio is really good. I'm using it with the USB connection (haven't tried the optical input yet), Windows 7 laptop, and Bose AE 2 headphones. Most of my music files are variable bit rate mp3 with a high of 328k to a low of 128k. The audio preformance has the warmth of a tube amp with the detail and clairty of a solidstate amp. I'm really like it, highly recommend.
Summary: I packed the D1 on my summer trip and have it hooked up to a Mac Air and Bose Soundlink Bluetooth speaker. It sounds great! I was able to easily compare it with a Bluetooth and 3.5mm cable hook-up and it's quite noticeable. There is ample bass and the midrange is clearer. If you care at all about sound quality, the D1 is a pretty inexpensive way to improve your tunes.
Pros: Good build and comes with the 3.5 mm audio cable.
Cons: Have grippy or suction style feet so unit can stay in place.
Summary: This is a good unit. Its small, it provides better amplification, and you'll clearly hear the difference in the dynamic range in volume and tone. This is particularly useful if you are using full size head phones of high quality.
Pros: small, versatile, good value, great improvement over in computer amplifier