Amps & DACs
The HRT MicroStreamer is the perfect solution if you're looking for a headphone amp & DAC strictly for your computer, tablet or smartphone for on the go use. The MicroStreamer has a an easy-to-use interface with simply a USB input, headphone jack, and a fixed-level, low impedance 2.25V line output. The unit powers directly from a computer, and despite it's small dimensions, is able to drive most headphones with competance. Volume is controlled by a digital 'slide' control on the host computer's music playback software. The MicroStreamer allows native-resolution playback of music material up to 24-bit/96k and is indicated by the LED indicators on the side of the unit displaying the current sample rate (32k, 44k1, 48k, 88k2 & 96k). HRT's upstream utility allows the MicroStreamer to be updated right from the computer's desktop as firmware updates become available. Simply put, this sleek little aluminum box that's designed and manufactured in California, USA, will leave you with very little to worry about and a whole lot to love. Apple iOS compatibility requires use of the appropriate lightning or 30-pin Camera Connection Kit on the following devices: iPad (all generations), iPhone4 or newer running iOS7 or iPod touch 5th generation (iOS7).
- compact & portable headphone amp & DAC accepting up to 24/96 material
- supports 32k, 44k1, 48k, 88k2 and 96k sample rates, identified by LED light
- plug and play w/ standard 1.0 audio drivers, upstream utility for fast firmware upgrades
- asynchronous mode operation eliminates jitter
- designed and manufactured in Southern California
What's In The Box:
- USB cable
- Cloth carrying case
- DAC option: no
- Amplifier Type: DAC/Amp Combo
- THD at 1V output: THD+N (1 kHz Full Scale): .002% (line), .008% (headphone)
- Frequency Response: +0dB / -.4dB
- Dimensions: 2.5
- Amplifier Group: Other Amps
- Home Use: yes
- Portable: yes
- Balanced: no
- DAC: yes
- Signal-to-Noise Ratio: DC to 30kHz: 18uV RMS; A-weighted: 105 dB
- Inputs: USB
- Outputs: 1/8 line level, 1/8 headphone jack
- Output Impedance: 50 Ohm (line), .5 Ohm (headphone)
- Output Power: up to 140mW (headphone)
Posted by Welly Wu from West Orange, NJ on 2013-07-30
Recommend Product: Yes
Pros: Affordable, wide compatibility, portable, superior sound quality
Cons: Not as thin and light as a USB thumb drive
On the drawbacks side, it is not nearly as portable as a traditional USB thumb drive. If they could find a way to shrink this product to look like a USB thumb drive without comrpomising sound performance with a future refresh of this product, then HRT will have won the world series.
It's good to see HeadRoom offering this product to cater to a wider and more diverse range of consumers. When they do offer their refreshed product range of HeadRoom headphone amplifiers and DACs, they will have to beat this HRT MicroStreamer at the same price point or a little less. That will be very very difficult to accomplish, but I trust HeadRoom will produce their own winner that will compete next to this one by the end of 2013. The HRT MicroStreamer is a blazing hot product for this summer.
I upgraded to Ubuntu 14.04 LTS 64 bit development branch using Linux kernel 3.13 64 bit and I can verify that my HRT Micro Streamer USB asynchronous DAC works with 24 bit 44.1/48/88.2/96 kHz music files. All GNU/Linux users should upgrade to Linux kernel 3.13 32 or 64 bit or higher in order to fix a buffering issue that caused Linux kernels 3.12 32 or 64 bit or lower to produce skips in the sound using 24 bit 48 kHz or higher resolution music files.
You can contact me at email@example.com for more information on how to do this in the future if you use GNU/Linux.
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Posted by dale from Akron Ohio on 2013-05-02
Recommend Product: Yes
Pros: Excellent sound, small size
HRT supplies a 19-inch USB cable with the MicroStreamer, which I replaced with a 12-inch cable. Since the asynchronous DAC re-syncs the bits after they arrive at the DAC, I assume a short USB cable should suffice to preclude any cable-induced losses. On the other hand, when using the Line Out jack to feed the DAC's analog output to a headphone amp or power amp that has its own volume control, that interconnect cable should be as high in quality and as short as possible.
The key feature that distinguishes this mini-DAC from other audio devices that perform the same function is having a DAC and headphone amp** together in one little plug-in device. For people who have been using the headphone jack on their desktop or laptop computers, and assuming that those computers have USB ports, they should expect better sound using the MicroStreamer instead of the computer's headphone jack. The actual improvement with my computers is a cleaner sound with a greater sense of "space" and "air" around the instruments. The tiny size for what it does may suggest to some audiophiles that the MicroStreamer's sound would be of much less quality than the typically separate DACs and headphone amps selling for a much higher price. My feeling is that for good quality computer audio played on the typical dynamic headphones that will be used with a small DAC/amp like this, the sound quality of the MicroStreamer is more than adequate.
**While I don't have the original text in hand, I recall a designer of one of the first mini-DACs (HeadStreamer, DragonFly et al) stating that the mini-DAC does not contain a headphone amp per se, but that it provides a variable-volume signal sufficient to drive an average dynamic headphone.
Performing comparisons today with the MicroStreamer and AudioQuest DragonFly mini-DACs, playing a variety of 96 khz music tracks downloaded from the HDTracks and DownloadsNow sites, the main difference I hear is a smoother sound from the MicroStreamer, as though there were greater detail with less distortion, or conversely some rounding off of transients as one might expect with a valve/tube amplifier. It might be possible to pin those differences down to measurable performance data, but I've seen instances where measurements say one thing and expert ears (not mine) say something different, so I'll leave it go at the impression of smoothness and better musical detail, and someone else can determine whether it really sounds better or certain problems are being masked by the device's limitations in absolute accuracy.
When I performed listening tests of the HRT HeadStreamer, Audioengine D1, and AudioQuest DragonFly mini-DACs a few months ago, I found very little difference in their sound, and concluded that the differences weren't significant for music playback on those devices using mid-priced dynamic headphones. Since then I've looked at two new mini-DACs - the Meridian Explorer and the HRT MicroStreamer. If I had information that suggested the Explorer might sound significantly better than the MicroStreamer, I would have held off on purchasing the MicroStreamer until I was more certain of the differences. As it turned out, I got the idea that the MicroStreamer might be as good as the Explorer in the main despite the lower cost, so I went ahead and bought the MicroStreamer. If it turns out that the MicroStreamer is rated lower in sound quality than the Explorer by trusted reviewers, I won't be disappointed since the sound I'm hearing from the MicroStreamer is excellent, and a good value for what I paid.
Questions have come up as to whether a typical computer's USB port can supply enough power to run the MicroStreamer's DAC and headphone amp, to provide good volume especially in the bass where the greatest power demands occur, and to have enough headroom to avoid clipping or otherwise distorting the loudest most dynamic music passages. The answer is a qualified yes, since I have many FLAC format music tracks with a 96 khz data rate that have extreme dynamics which distort noticeably when sufficient power is not available, and all of those (so far!) play loudly enough on the MicroStreamer. The headphones I've tested the MicroStreamer with are the ATH ESW11-LTD, Soundmagic HP200, and Beyer DT770LE. There were a few tracks where I had the computer volume at maximum with the DT770LE, but that headphone does have a lower efficiency than the 32 ohm rating indicates. Still, caution is advised since I expect that many headphones won't play loudly enough with the MicroStreamer with some music tracks.
The MicroStreamer is a 63 x 30 x 11 mm aluminum box with the ports on either end as noted above, and with LEDs on the side for 32, 44, 48, 88, and 96 khz sample rates. It comes in a tiny cardboard box with a 19-inch USB cable and a very thin "bag" that presumably would hold the MicroStreamer and the cable, for carrying around in a computer bag or backpack. I'd suggest a better more protective case, such as Case Logic makes for carrying various memory cards or very small digital cameras.
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