Who can forget the the fabulous opening to the 1994 MTV Video Music Awards. Michael Jackson and Lisa Marie Presley walking on stage and proclaiming, "... Just think, nobody thought this would last." Less than two years later everyone else on the planet was proven correct when the two split up. They were clearly not a match made in heaven. Hailing from Bozeman, Montana the Headroom Ultra Micro DAC and Ultra Micro Headphone Amp are definitely not a Hollywood couple. In fact these to components really reach their full sonic potential when paired together. After a couple months with this combination I've really learned to appreciate the meaning of system synergy. The Ultra Micro DAC and Ultra Micro Headphone Amp together reproduced seriously good sound with every pair of headphones I plugged in to them. What follows is my complete review of this match made in Montana.
Every audiophile who owns a pair of headphones is familiar with HeadRoom. Founded by Tyll Hertsens in 1992 HeadRoom is the defacto standard for headphones, headphone amplifiers, and all the related components and accessories. In fact I've been a customer for several years beginning with my purchase of Sennheiser HD600s. I followed these up with a pair of Grado RS-1s and Etymotic ER4-Ps. When the time came to purchase my Ultimate Ears ue11 Pro earphones I purchased them directly from the manufacturer only because HeadRoom didn't offer this custom model. Needless to say I've personally experienced HeadRoom's great service over the years and can vouch for the great people working there.
I had never heard a HeadRoom Amplifier or DAC until the review units arrived here at Computer Audiophile. Even though HeadRoom publishes wonderful photos of its products online, I was still surprised by the small size of the Ultra Micro DAC and Headphone Amp. I'm still not sure how HeadRoom slips such quality components into a Headphone Amp and DAC each weighing in at 8.8oz and only 4.5" x 3.5" x 1.5" in size.
The Headphone Amp is a Class-A biased DC-coupled amp with totally separated left and right channels. The op amp is a Burr-Brown OPA627, that clearly separates this Ultra Micro amp from the standard Micro version. The Ultra Micro Headphone Amp has the unique and frequently discussed around the Internet, HeadRoom crossfeed circuit. Briefly, this circuit helps manage the typical imaging problems refered to as the blob in your head when listening to headphones. This amp features three stages of gain, low, medium, and high. With all of my headphone, including the HD600s, I was satisfied using the medium setting. The nicest feature in my opinion is the dual input switch. This worked fabulous for me as I compared different DACs via A/B tests. I am not a huge fan of A/B tests as I prefer to listen to components over an extended period of time to gain familiarity. But, it certainly doesn't hurt to have a couple DACs connected and ready at the flick of a switch. Nothing interrupts a listening session like changing sources and moving the interconnects etc ...
The Ultra Micro DAC contains the Cirrus Logic CS4398 DAC chip and Analog Devices AD1896 Asynchronous Sample Rate Converter. Both of these chips are flagship type components in each manufacturer's lines according to HeadRoom. The DAC's inputs are optical, coax, and USB. Many readers will be interested in the USB input as this is a very popular method of connecting laptops and desktops with or without S/PDIF outputs. The USB chip is a TI PCM2902 that converts the USB signal to S/PDIF. Sure its possible to use a USB to I2S combination like other DACs, but considering the size and price of the Ultra Micro I think this is a trade-off I'm willing to make.
Speaking of trade-offs, there are a couple other minor complaints I have with these two HeadRoom components. First, I am not a fan of the input and output cable requirements. While each input and output uses "standard" sizes, they are the least popular sizes available. For example, the USB input uses a mini-B terminated USB cable. These are frequently used in digital cameras and mobile phones. Mini-B type USB cables are certainly not impossible to find but they are much less common than Type A to B terminated cables. In addition you are likely to have very few options with a Mini-B cable when it comes to length and manufacturer of the cable. In addition to the USB cable, the line out and coax input use Mini 1/8" plugs. Certainly not my favorite or first choice. Again, not the end of the world just a small compromise that likely had to be made due to the small size of the DAC. My second complaint is the large ugly power supplies that come with each component and the thick somewhat stiff power cables attached to them. The Ultra Micro components are probably going to be used on a desktop near a computer and the small size of the amp and DAC will work perfect in this situation. But, the power cables are a little thick and stiff to weave nicely around a tidy desktop. The power bricks are pretty large and will surely need to be hidden behind a desk as they are rather unsightly. Fortunately the people at HeadRoom have already thought this one through. The HeadRoom Desktop Power Supple (DPS) is available and is similar to the Musical Fidelity X-PSU. Each component connects to the nice looking DPS and the DPS connects to the power outlet with a standard power cable.
As long as I am on a roll here I will throw in one more thing into the mix. Behind the Ultra Micro Headphone Amp volume knob there is a clearly visible little gray metal hex nut. This gives the amp a little bit of a DIY look to it and could easily be changed by HeadRoom. I suggest a simple black hex nut as the short term solution and maybe something more elegant in the long term. Alright, enough complaining about the Ultra Micro products. These components sound very good so it's time to focus on the sound.
Note: All my listening was done through iTunes on a MacBook Pro. I used AIFF files exclusively. 99% of them were 16/44.1 and the other 1% were 24/96 ripped DVD-Audio discs.
Over the last couple months I listened to the Ultra Micro DAC and Headphone amp through loudspeakers, headphones, USB, S/PDIF, and just about every other configuration one can imagine. I used the Ultra Micro DAC with PS Audio headphone amp and the Benchmark DAC1 PRE (analog inputs), and connected it to my Macintosh / McIntosh / Avalon Acoustics main system. I also connected the Ultra Micro headphone amp to many of the DACs I have around here including the PS Audio DLIII and Benchmark DAC1 Pre. After all of my extended listening sessions and A/B tests the combination that sounded the best was when I paired up both Ultra Micro components together. There just wasn't that system synergy when I used a different DAC or headphone amp. The Ultra Micro components really sing when used together. Please don't misunderstand that statement. It certainly does not suggest each component is less than capable of performing in another combination. In my opinion the best sound I achieved was using both HeadRoom components together.
The two Ultra Micros really are a perfect pair. The sound is closer to the Benchmark DAC1 sound signature than the PS Audio DLIII and GCHA sound. Using my Sennheiser HD600 headphones for most of the review sessions the sound was extremely tight and controlled. Possibly a bit more controlled than I am used to. The sound was a tiny bit constricted in the upper mid range while listening to a few of the Reference Recordings HDCD 16/44.1 Minnesota Orchestra albums. This was certainly not a showstopper though. The rest of my music collection sounded really good through the Ultra Micro combination. In preparation for the new Metallica release Death Magnetic, I made sure to pump some Master of Puppets and ...And Justice For All tracks through the HeadRoom Ultra Micro stack. The sound was really enjoyable on both albums. The tightness and control of this combination was very evident on tracks from ...And Justice For All where Jason Newsted's bass can sound a bit wobbly if left untamed by the right components. Listening to my usual and very familiar Sonny Rollins and Chet Baker albums I really turned up the volume on the Ultra Micro Headphone Amp to see how much muscle & finesse it actually had. One thing is certain with this amp. It will not run out of power before possibly blowing your ear drums. This thing can really kick out the volume. The Ultra Micro Headphone Amp was also no slouch in the finesse department when the volume was cranked. Sonny Rollins' Way Out West from Analogue Productions sounded as lush as ever at high volumes. If anything, my ears gave up before the Ultra Micro combo displayed any fatigue. You surely won't want to listen at high volumes on a regular basis for an extended period of time, but it is certainly nice to crank up the tunes once in a while and it's reassuring to know you have the reserve power to do it.
The Ultra Micro DAC and Headphone Amplifier from HeadRoom are a really nice combination for many different situations. The small size and high performance should be very attractive to potential purchasers. It is never a bad thing to shrink the size of your components as long as performance does not suffer. The Ultra Micro components definitely don't suffer any performance hits because of their size, but they do have some design compromises that should be considered before a purchasing decision is made. Retailing for $699 each the Ultra Micro DAC and Headphone Amp have some stiff competition in this price range. Fortunately each of the Ultra Micro products can be purchased separately. Try purchasing just the DAC portion of an all-in-one unit from another manufacturer and I bet you don't get very far. HeadRoom offers a 30-Day Satisfaction Guaranty on all purchases, so what have you go to lose? Chances are you'll be more than satisfied with one or both of the Ultra Micro products.
More information and ordering details at www.HeadPhone.com
Detailed photos of the Ultra Micro DAC and Ultra Micro Headphone Amp