FEATURESCustom-designed circuitry for clean, truthful reproduction of recorded audioDACport HD does not add any sound coloration — It preserves artist’s intentionAudiophile-grade AK4490 D/A converter plays HD music with bit-perfect accuracyCustom clocking technology eliminates jitter for listening without fatigueAmpExtreme™ Technology offers wide soundstage, clarity, detail and volumeErgonomic, side-mounted rotary volume control for single-handed adjustmentDigital volume adjustment with perfect tracking keeps L/R channels always in balanceNo power adapter or batteries needed — uses USB power from your laptop1/8-inch headphone jack drives the most advanced headphones on the marketAircraft-grade aluminum chassis for scratch protection and durabilityGENERAL SPECSPower SupplyUSB bus (no external power supply needed)Tablets and SmartphonesDue to high output power, a power bank or hub may be requiredHeadphone AmpAmpExtreme™ technology with bipolar power supplyRequired cableUSB “micro B” cable, must be “Data cable”. Charging-only cable will not work.Gain Switch20dB rangeAnalog SuppliesTriple-filtered ±9 V dual analog power supply railsDigital SuppliesFive independent, high-efficiency, switch-mode power suppliesChassis MaterialAircraft-grade aluminum, hard-anodized for scratch resistance, black, laser-engravedUnit Dimensions3″ (7.6cm) L, 1.1″ (2.9cm) W, 0.4″ (1.1cm) HUnit Weight72 grams (2.5 ounces)