Can a tiny $39 amp make your headphones sound a lot better?  The
Audiophiliac listens to two outrageously fine Firestone
products: the $199 Fireye DA USB headphone amp and the $39
Fireye Mini portable headphone amp.  The Firestone Mini
headphone amp, shown with the cables that come with it.
(Credit: Firestone Audio)  Some "portable" headphone amplifiers
aren't all that small, but the Firestone Audio Fireye Mini is
downright tiny.  It's just 1.5 inches by 1 inch by 0.5 inch, and
the soft-rubber-shelled amp weighs almost nothing, so you can
hang it off your iPod, iPad, iPhone or any device with a 3.5mm
headphone output. Plugging in a headphone turns the Mini on and
lights a bright blue LED, unplugging turns the amp off. Charge
the Mini via the USB connection and it'll play for up to 24
hours. It's available in green, gray, purple, red, and white.
The Mini is no giant-killer, but it definitely bumped up the
detail and resolution of my Monster Turbine Copper, Ultimate
Ears UE-4, and vPulse in-ear headphones. Th