If you own a pair of high impedance headphones or want to bring back to life a pair of earbuds, a dedicated headphone amplifier is definitely a great way to get your headphones to perform at their best!
UAMP is a portable headphone amplifier with custom equalizer that is compatible with 16Ω to 300Ω headphones.
UAMP is a small and compact portable headphone amplifier, measuring only 43mm x 43mm x 10.4mm and weighing only 26 grams (same weight as a standard AA battery).
Thanks to the high output power and low output impedance, UAMP allows you to easily drive high impedance headphones on your phone and increase the volume much louder (+8dB) without sounding distorted. UAMP works with phones as well as laptops, tablets or other audio devices with 3.5 mm audio sockets.
Included with the UAMP portable headphone amplifier with equalizer is a charging cable, a long 3.5mm stereo audio cable, a short 3.5mm stereo audio cable, a felt carry bag, a clip and velcro cable tie.
UAMP is powered on and off by holding the rectangular button for 3 seconds. This same button also controls five different EQ settings, which include: Flat EQ (green LEDs), Bass & Treble Boost (blue LEDs), Bass Boost (red LEDs), Treble Boost (cyan LEDs) and Custom EQ (purple LEDs). The volume level is controlled via two dedicated buttons denoted by the + and - symbols.
The custom EQ setting allows you to define the bass and treble and it is accessed by pressing the EQ button and volume+ at the same time. To set the custom level of bass, hold the volume+ or volume- buttons to the desired level and press the EQ button again to save the bass setting.

To set the custom level of treble, hold the volume+ or volume- buttons again to the desired level and press the EQ button again to save the treble setting.
To check the battery level of UAMP, simply hold both the volume+ and volume- buttons. Each LED denotes 25% charge so three flashing LEDs means 75% battery charge remaining.
The LEDs on UAMP stay on by default, but if you do not want the LEDS on you can turn them off by entering "Dark Mode", which is entered via the Custom EQ setting (purple LEDs). Once you are in the Custom EQ setting, hold both the EQ button and volume- buttons at the same time to turn the UAMP's LEDs off.