HeadRoom Micro Amp and Micro DAC 
        
          
              
            Micro Amp 
              
            Micro DAC 
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        I love HeadRoom, but mine is no simple
        fanboy crush -- Ive got good reasons for it. First, it was a HeadRoom amplifier, the
        discontinued Little, that introduced me to the real joy of headphones and hooked me on
        quality sound. Without HeadRoom, I probably wouldnt be writing for GoodSound!
        now. Second, the release two years ago of the Total BitHead USB-enabled, battery-powered
        headphone amp illustrated the inventive approach HeadRoom takes not only to product
        development, but to company image as well. Third, in addition to its own website, www.headphone.com, HeadRoom has
        supported headphone sites such as www.head-fi.org
        since, well, before there was www.head-fi.org. And fourth, HeadRoom folk such as
        its president, Tyll Hertsens, are some of the friendliest, most approachable people
        youll find. 
        Description 
        HeadRooms Micro DAC digital-to-analog converter ($299
        USD) and Micro Amp headphone amplifier ($299) have the same casework; only their
        faceplates and innards differ. Each has an aluminum body 1.5"H by 3.5"W by
        4.5"L. The DAC weighs 9 ounces, the Amp 9.6 ounces; both weights include the
        batteries. That means the Micros weigh just over a pound together; in contrast, the Total
        BitHead weighs 5.5 ounces. You dont need to be a he-man to carry around a pound, but
        its a noticeable amount of weight. If youre walking around the city all day,
        the Total BitHead is probably the better choice (hence its inclusion in HeadRooms
        Mobile line). 
        The Micro DAC and Amp cases have a slight convex curve and
        rubber surrounds around their front and rear panels. These surrounds have long indents on
        the top and ridges on the bottom, which allows the units to be secured to one another when
        stacked. The connection is tight enough that you can move them around on your desk without
        worrying that the top one will fall off. 
        Each rear panel has two thumbscrews (one on each end) that
        allow the user to remove the plate to insert the two 9V batteries that power each unit.
        HeadRoom claims a battery life of 15-18 hours for the Micro Amp, eight hours for the Micro
        DAC. Dead center on each rear panel is an input for a wall-wart power supply (provided).
        The batteries are inexpensive, and the convenience of not having to find an outlet meant
        that I used the Micros exclusively with batteries. I found HeadRooms claimed battery
        life to be conservative. 
        One thing all the Micros faceplates have in common is
        HeadRooms new logo, ablaze with a red LED in the upper left corner. Starting at the
        DACs front left is the line out on a 1/8" output, then a 1/8" input for
        optical or coaxial digital signals. It wasnt as easy as I had hoped to find a
        mini-optical adapter for a regular TosLink cable. It took me three RadioShacks to find
        one; apparently, this adapter has been discontinued. You may want to make sure you have
        one on hand if you plan to use the Micro DAC with such a connection. Next is a USB input
        so that you can use the Micro DAC with your computers, then two identical switches: the
        input selector (optical, coaxial, or USB) and the power switch (external or battery
        operation). 
        Like the Total BitHead, the Micro DAC uses the Texas
        Instruments/Burr-Brown PSM2902 USB chip. Unlike the BitHead, the DAC uses this chip only
        to convert the USB signal into a S/PDIF digital signal, which is then processed by a
        Cirrus CS4398 DAC chip. The Micro DACs coaxial and optical inputs can accept word
        lengths of 16 to 24 bits at 44.1kHz, 48kHz, or 96kHz. 
        On the left of the Micro Amps faceplate is a line
        input, then the headphone output, both 1/8" connections. In the middle are two small
        switches: the first toggles HeadRooms Crossfeed circuit on and off, and the second
        selects among three gain levels: High, Low, and Medium. Next is a volume knob thats
        big enough to grab easily, or find by touch if your amp is in a briefcase or backpack.
        Last is the power switch, to select external or battery power. 
        HeadRoom has a
        lot to say about their Crossfeed circuit on their website. Briefly, it sends some of
        the signal from the right channel to the left, and some of the signal from the left
        channel to the right. HeadRoom claims this helps create a coherent aural picture instead
        of a separate blob of sound in each ear. The usefulness of Crossfeed seems to vary with
        the recording. 
        HeadRoom also provides some neat ways of carrying the
        little Micros around. The Micro Strap goes around the Micro Amp, and provides a platform
        on which you can secure your MP3 player with Velcro. A kickstand lets you tilt the player
        up so that you can see it clearly while sitting at your desk. When youre ready to
        head out the door, you can carry the Micros in a Micro Bag. To use the Amp and DAC
        together when on the go, youll need the Micro Strap Extender, which secures both
        units, and a bigger Micro Bag. If this is confusing, a call to the nice people at
        HeadRoom, at (800) 828-8184 or (406) 587-9466, will get you squared away on which bag
        suits your needs. 
        Listening 
        I did most of my listening with the Micros using my laptop
        computer and the iTunes library Ive compiled for my iPod. The tracks have varying
        bit rates, but nothing is less than 192kHz. I also used the Micros with a Sony SCE-775
        SACD player with an optical cable feeding the Micro DAC. I used both Grado SR-60 and
        Etymotic ER4P headphones, but the specific review observations here refer exclusively to
        my listening with the Etymotics. 
        The first album I used to evaluate the Micros was David
        Johansen and the Harry Smiths Shaker [CD, Chesky JD236] -- good sound and
        toe-tappin blues. On "Let the Mermaid Flirt with Me," instruments such as
        brushed drums and acoustic guitar were reproduced with truthful timbres. This was one of
        those recordings nicely helped by HeadRooms Crossfeed circuit. The tracks
        bizarre separation of instruments in the left and right channels works fine on speakers
        but is unsettling on headphones. Crossfeed helped me enjoy the music without obsessing
        over the instruments placements inside my head. 
        I then played the always fun (and eponymous) album by the
        Scissor Sisters [CD, Universal B0002772-02]. The opening percussion and guitar of
        "Take Your Mama" were crisp and clean, but I knew within seconds that the
        batteries in either the Micro Amp or the Micro DAC were dying -- the sound quickly became
        distorted. Luckily, I had extra batteries ready to go. Up and running again, I noticed how
        deep and powerful the bass was. It was even more noticeably deep and controlled on Their
        Law, the new greatest-hits collection from The Prodigy [CD, XL XLCD190]. 
        I chose the Scissor Sisters and Prodigy albums because I
        listen to both frequently on my iPod. This gave me a good baseline from which to compare
        the Micros. The difference was like night and day. My overall impression of the sound
        quality of these albums went from "OK" to "very good." No need to
        worry that the Micros werent doing their job. 
        On recordings such as Bob Dylans Desire [Columbia
        CH 90318], I was impressed with the soundstage the Micro combo portrayed. The tambourine,
        piano, and drums on "Isis" offered a very wide picture, not the narrowly
        confined one that headphones sometimes produce -- and the tambourines sound was
        incredibly lifelike. 
        The most noticeable improvements introduced by the Micros
        were a bigger soundstage, better resolution, and a wider dynamic range. Played on my iPod
        or directly from my computer, these same tracks sound pretty lifeless, their dynamic
        ranges inconsistent with those of the original recordings. The Micros helped fix that
        problem handily.  
        Comparisons 
        I compared the HeadRoom Micros with two other headphone
        rigs: HeadRooms own Total BitHead, which Ive used for laptop listening since
        2004, and Benchmarks DAC1, which isnt portable but has received widespread
        enough praise to become something of a . . . benchmark. Neither competed directly with the
        Micro DAC-Amp, for two reasons. First, the Total BitHead retails for $199 and the
        Benchmark for $975; neither is in the price class of the Micros, which together cost $598.
        Second, the Total BitHead allows for similar functionality as the Micros, but the
        Benchmark has no USB input and cant be used as a portable.  
        The Micros blew the Total BitHead out of the water. On
        "Belleville Rendez-Vous (French Version)," from the soundtrack of The
        Triplets of Belleville [CD, Higher Octave 96811 2], the Micro Amp and DAC were better
        able to catch nuances and resolve detail. Toward the very beginning of this track are some
        sounds that are often imperceptible through speakers, but the DAC-Amp displayed them
        perfectly through headphones. Another example of this occurs about two minutes into the
        track, when some percussion instruments enter. The Micros articulated these sounds well
        and made them distinct from other instruments in the mix. 
        The Total BitHeads presentation of the music was much
        more laid-back than the Micros. When the bass kicks in on the Belleville
        track, the Micros almost had me up and dancing; the Total BitHead only made me tap my
        feet. Depending on your application, this might be preferable -- with the Total BitHead, I
        was able to attend to e-mail and other online tasks while still enjoying the music, but
        the Micros had me paying too much attention to the music to get anything else done. The
        Micros replace the sweetness of the Total BitHead with a more detailed, precise sound. 
        Still, the Total BitHead is much smaller and lighter, and
        attaches nicely with Velcro to the back of my laptops screen. That isnt going
        to happen with the Micros. The BitHead can also run entirely off power derived from its
        USB connection to the computer; no such luck with the Micros. Ill continue to use
        the BitHead with my laptop, because portability is important for me. If I had a desktop
        computer, however, the better sound of the Micros would inspire me to replace the BitHead
        with them. 
        Because this review focuses on the combination of the Micro
        DAC and Micro Amp, thats how I compared them with the Benchmark DAC1; I didnt
        evaluate the Micro Amp separately. The Micros gave a wider soundstage and a mellower sound
        than the Benchmark, which offered better instrumental timbres, more detail, and deeper
        bass. These characteristics were easily heard using one of my perennial favorites, Charles
        Minguss Mingus Ah Um [CD, Columbia/Legacy CK 65512]. On "Goodbye
        Pork Pie Hat," the Micro combination made the instruments seem spread out in space
        but failed to offer the last bits of detail -- such as the fingers of one of the horn
        players tapping his instrument. Similarly, the Benchmark was better at separating
        instruments from one another. The upbeat opening of "Better Git It In Your Soul"
        has lots of instruments and at least one voice. Listening to this track through the
        Benchmark, I heard very sharp images of each and every one of these sounds, but in a more
        confined space than through the HeadRoom Micros. The images of the instruments were softer
        through the HeadRooms, but the space the musicians occupied extended well past the
        soundstage the Benchmark provided. 
        Conclusions 
        The good news for headphone enthusiasts is that there is
        now a plethora of products available to enhance their listening pleasure. Thats also
        the bad news. You can choose from the ultraportable Total BitHead to portable but bulky
        solutions such as the Micros, tubed headphone amps, and beyond. You need to consider which
        characteristics are important to you, how you listen to headphones, and how much you want
        to spend on a headphone system. Theres no easy solution, so allow the auditioning
        process to be a fun addition to your hobby. 
        HeadRooms Micro Amp quickly took over from the Total
        BitHead as my favorite inexpensive headphone amplifier. The sound it produced simply had
        more clarity and a feeling of more power behind it. But unlike the BitHead, it lacks a USB
        input, so theres a tradeoff. To add USB functionality to the Micro Amp youll
        need the Micro DAC, but the combo costs three times as much as the BitHead. If I sat in
        front of a computer all day listening to headphones, Id probably consider the money
        well spent. If more portable players had digital outputs, the setup could be invaluable.
        But the Micro combo costs $598. The Total BitHead wont give you the same
        performance, but it will give you better sound than your computer or iPod will on its own,
        and will keep $399 in your pocket. 
        The Micro DAC and Micro Amp perform as well as anyone could
        hope, are finished to high standards, and fill the largely ignored niche of USB-enabled
        portable audio components. HeadRoom provides excellent customer service and aggressively
        supports headphone hobbyists. With the Micros, my love affair with HeadRoom products
        continues. 
        ...Eric Hetherington 
        Prices of equipment reviewed 
         
        
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