The HeadRoom Portable Micro Amp has upsides, but doesn't offer as much value or audio quality.
When it comes to personal entertainment, few experiences are more deliciously self-indulgent than listening to great music on a pair of exceptional headphones connected to a really good headphone amp.
The HeadRoom Portable Micro Amp looks as high tech as the Grado RA1 does retro. Both devices are hand built, but the Micro’s extruded-aluminum enclosure gives it a cyberpunk vibe. The Micro has both analog and digital inputs (optical, coaxial, and USB), a built-in DAC, a three-position gain switch, and an internal Li-ion battery. But we found that the amp wasn’t nearly as powerful when it came to an iPod’s output unless you crank up the gain, and it had a very difficult time driving the Ultrasone cans. Switching gain to High colored the audio, rendering it too bright; and Medium boosted the signal just enough if the source and the amp were running full tilt. This was less of an issue with the Sennheiser phones, and the amp nearly blew our ears out when we plugged in the highly efficient Shures. The problem disappeared when we used a notebook as our source (via USB) and relied on the Micro’s built-in DAC.
Portability’s cool, but if the amp can’t drive your favorite phones, what’s the point?
Built-in DAC. Runs on either Li-ion battery or AC. Rugged construction. 
Has difficulty driving professional headphones. 
MacGeorgeHB
February 10, 2009 at 1:23pm
But I think I'll keep the Grado, anyway, since I've just placed an order for it with Grado. I like the clarity and range of the Grado's reproduct on. I have been saving my pennies for years to be able to buy one, but finally splurged and used plastic. With all the listening I do, it's well worth it. And the Headphone unit may be too, depending upon one's tastes. Trialling the Grado amp at stores and listening to a friend's just kept making me regret not having bought one when I did have the cash, and so after discussing it with "she who must be obeyed" I took the plunge. Desperate times require desperate measures. But about the amp under review here, please do consider the cans you are using before purchasing the amp. Try to find a store that will let you try the amp with your preferred cans before purchasing. $399 is a lot of money in these times.
