Review on Headphone Amplifier Portable 3000MAh Computer by Carmen Thomas

As another reviewer mentioned - don't let the packaging fool you - a plain white box labeled "Enjoy HD shock!" (obviously the same box is used for HDMI audio extractor, HDMI 1x2 splitter, HDMI uses 1x3 splitters, a 3x1 HDMI splitter, etc. But inside you're quickly greeted by a polished, matte black aluminum body with plenty of bells and whistles.Connections include the typical mic-in and speaker-out (6-300 ohms), solid full-range -Volume control potentiometer with on/off switch and red LED, a second LED indicating USB input power glowing red/blue (charging/fully charged) on the back, along with the USB port for charging (no, they make it clear that USB is for power only and not for input/computer output signals). And they've also thoughtfully included a 6dB high/low gain switch Speaking of thoughtfulness, they've outdone themselves with cables - a long enough USB cable, a short TRS cable with a 90 degree bend, and even another long TRS cable with a straight end 0.0003 percent, signal-to-noise -Ratio less than 120dB, Frequency Response 20-20KHz +/- 3dB, 2000mAh lithium battery, 3.7V). And yes, if you're picky about Chinese products, I acknowledge (and relish) this quote below their warnings: There is a battery in the product, do not open it privately. lol. Regardless, the headphone amp works great!