Originally Posted by kwlinca
Something to consider other than these options is the HRT HeadStreamer. It's got asynchronous USB and analog (post-dac) volume control. I use this with a few laptops running Fidelizer 2.1 & JRiver MC17 into UERMs. The JRiver volume slider controls the analog attenuator in the HRT. The only downside is the 24/96 limit. Customer service is incredible; Kevin Halverson (CTO) even helped me optimize my JRiver settings. The D7 carried too much electrical noise to be usable for me. The D1 is reported here on HF to have to much gain (too loud) for custom IEMs.
I have both the ibasso D7 and the HeadStreamer. While I would definitely recommend the HeadStreamer to anyone looking for a good unit under US$150, I still think the D7 has a more refined sound. The HeadStreamer is pretty good quality--some people note it as a bit "treble hot", although I think I'd slate it more as a tad "presence hot" which by itself isn't too noticeable, but when A/B tested against the D7, sounds a bit harsher in comparison.
The main thing is that the HeadStreamer is a more ad-hoc product. While the D7 has various output jacks and a gain switch to make it more than just a headphone unit, the HeadStreamer has no extra output devices or features. The HeadSteamer is simply a dead-simple headphone unit, and does it very well. And the way it handles the volume control makes it even more simple--eliminating the confusion for many newcomers around how to handle multiple volumes in the chain.
My only complaint with the HeadStreamer is that the amp is not very powerful, and is no louder than the built-in headphone jack on my MacBook Air, and so I sometimes have to put the volume to 100% when using my DT880's w/albums recorded at lower levels (however, I should point-out that the quality doesn't deteriorate at all, even at 100% volume). I can definitely see the HeadStreamer as being great with IEMs, but bigger, harder-to-drive phones could be an issue.
With shipping, the D7 was ~US$200 and only available direct from ibasso, while the HeadStreamer was only ~US$140 and available via various vendors on Amazon (and since I'm a Prime member, the shipping was free for me). The D7 also has the goofy USB driver power warnings (see the "D7 first impressions" thread) since it uses a newer USB sound standard than most devices, and around 1/3 of the time when I come out of sleep mode, I have to reboot my Air to get it to recognize the D7 again--more of a nuisance than anything, but the HeadStreamer has no such issues (it "just works").
Basically, if the price difference isn't an issue and you're specifically looking at sound quality (unless of course, you prefer a slightly higher treble/presence signature) and/or want the flexibility of all the other output options and having a 192kHz sample rate, then the D7 is the way to go. However, if you just want a simple, headphone-only DAC/amp unit with high-quality sound, and want a somewhat lower price point, then the HeadStreamer is definitely a really good option if you don't have really hard-to-drive phones. In terms of someone looking for a similar entry-level unit, I'd put the HeadStreamer above the Fiio E10 (usually ~US$75) in terms of sound quality (a bit clearer overall and a more natural soundstage) although the E10 has a somewhat more powerful amp (maybe by ~20%) and has bass boost functionality.
Edited by bluishgreen - 5/23/12 at 7:38am