• Fully balanced headphone amplifier: Adopting fully balanced amplifier circuit and innovative circuit design with built-in voltage booster circuit, the amplifier circuit of U5 PRO always works at a high voltage of ±14V even if input DC 5V, with wide frequency response extension, excellent transient response, excellent purity and transparency, and good dynamic range.
• Easily to drive low or high impedance headphones: For a total power output of up to 1500mW under a 32Ω load, U5 PRO can easily power headphones with any low or high impedance (18-600Ω). Volume knob allows you to smoothly adjust volume without any undesirable noise nor any channel imbalances.
• Classic OP+BUF architecture: U5 PRO adopts OP42 and BUF634, classic OP+BUF architecture, and pure DC amplification circuit, ensuring every note is rendered with outstanding clarity and purity. Designed with four independent paths, it delivers exceptional sound quality, making it an ideal choice for audiophiles.
• Pure analog design and pluggable op amp: Pure analog amplification circuit and analog control, show you the truest sound, all aspects are in the top-class such as sound field, sound position, details etc. Pluggable op amp socket design, OP42 can be replaced by OP17, AD797, AD843, AD847, and OPA627, convenient to upgrade different op amps to enjoy other sound styles.
• Most cost-effective amp on the market: Mini size and exquisite appearance, and with low distortion, high power and a pure, uncolored sound, you'll experience subtle details and shocking swings in your music effortlessly. U5 PRO, the best helper for all XLR/4.4mm headphones to improve their sound quality.

• Audio input: stereo L/R XLR (3-core, female)
• Audio output: XLR (4-core, female)/4.4mm
• Output power: ≥1500mW(32Ω)
• Matched headphone impedance: 18-600Ω
• Max output amplitude voltage: ±14V
• Frequency response: 20-30KHz
• SNR: ≥110DB
• THD: 0.005%
• Input voltage: DC 5V (≥1A)
• Dimension(W*D*H): 70*82*38mm/2.76*3.23*1.50in
• Net weight:172g/0.38lb
• Package weight: 300g/0.66lb

User Manual & Driver of Douk Audio U5 PRO