As a music producer, DJ and audiophile, not to mention audio reviewer, I use my Shure E5c ear-phones in a large variety of applications. But the most common use for earphones or headphones today is with an iPod, an MP3 player or a laptop computer. Much like with a pair of speakers, if you want to take full advantage of your earphones, you’ll need a good power amplifier to drive them. An uninformed iPod or laptop owner you might be tempted to think: I can listen to my music as loud as I want to already, so why would I need better earphones or a headphone amplifier? There is some truth to this if your portable music player or computer is loaded with poor, over-compressed music. However, if you have good quality digital music, there is much to be gained from using a good pair of earphones and a headphone amplifier. Another scenario where a head-phone amplifier is indispensable is if you want to use a more difficult-to-drive pair of headphones (ones that have a high ohm rating), with a portable music player.
This time, the product under review is the HeadRoom Portable Micro Amp which retails for $399 on the company’s website www.headphone.com. For an additional $199, a Digital-to-Analogue (DAC) converter can be factory installed inside the amp module which provides optical and coaxial S/PDIF digital inputs and a USB input. My unit included the DAC option. In order to take advan-tage of the DAC, which works with samples rates up to 24-bit/96 kHz, the digital or the USB input must be used.
The front panel of the amp contains a mini-stereo line input, a mini-stereo headphone output, a volume knob and switches for crossfeed, gain and power. The rear panel contains a power connec-tor, a charge status LED, an optical/coaxial input, a mini-USB input and a pre-amp output. The Portable Micro Amp contains a 7.4 volt lithium ion rechargeable battery rated to last for about 20 hours on a single charge, which takes between 2 to 3 hours. The enclosure is manufactured out of heavy aluminium with a jet black anodized finish and rounded urethane bezels around the front and the back.
The HeadRoom Portable Micro Amp arrived at my house just in time before my business trip to Germany. Although I used the amp with a variety of components during my trip, my main source was a MacBook Pro laptop which can output sound via both optical and USB. But first, I began listening by plugging the headphone output from my laptop to the line input of the amp. This is not the best connection option, since the headphone sections of most devices are often of poor quality, but it is the most likely connection that most iPod and MP3 player owners will use. When using the headphone output, Headroom recommends setting the device’s volume to maximum and controlling the volume with the amp for best results. When listening to The Tribe Called Quest CD, which I ripped to iTunes in AIFF format, the results were actually pretty remarkable. I immediately noticed a fuller sound and the neutral characteristics of this amp. The bass sounded much deeper but also significantly cleaner – as a result I heard much more clarity in the mids and the treble. The sound was much less fatiguing. In addition to all of this, I really enjoyed the amp’s Crossfeed feature. When engaged, this feature blends a little of each channel into the other with a slight delay. So in-stead of getting the hard “in-your-head” kind of sound that earphones tend to produce, the sound-stage is brought forward and a sensation of imaging is enhanced. Music moved in front of me in a more natural manner when using the Crossfeed.
When I connected the optical output of my MacBook Pro to the optical input on the amp, things got even better. There was fluidness and an improved image to the sound that I would normally expect from a good standalone CD player. The background was absolutely silent. If there is one thing that my Shure E5c’s could perform exceptionally, it was bass. Now, thanks to the headphone amp and the DAC, the bass had full force and sounded just awesome. This little amp put the fun back into listening to music on my laptop. When listening to the Beatles Love album, I enjoyed a fuller harmonic sound. The dynamics of sounds and audio effects flowed naturally and transitioned very smoothly. In comparison, when I plugged my earphones directly into the laptop, the music became bland and dry.I also sent my laptop’s sound to the amp’s USB input, but my results were not as favourable as with the optical connection. Regardless of what source I listened to, a CD or an audio file or movie that was on my hard drive, there was a bit of harness to the mid and high frequencies and a lack of clarity. I tried a different USB cable and even a different laptop but the results were the same.
I’ve been using the HeadRoom Portable Micro Amp for nearly two months now and I’m com-pletely satisfied with it, with the exception of its USB quirkiness. The battery lasts and recharges exactly as advertised. Whether you use this amp with a laptop or a portable music player, it will raise your listening experience to an exceptional new level.
1-800-828-8184 (North America)
2007 HeadRoom Portable Micro Amp
Base price: $399
Price as tested: $599 (with built-in DAC)