Fosi Audio Q4 DAC Headphone Compact Mini Stereo Optical Digital Headphone Compatible with Supports Home Active Speakers Amplifier, 24-bit Amplifier,

The Q4 DAC headphone amplifier is designed with RCA/PC-USB/optical/coaxial inputs, and its 3.5mm headphone output is compatible with most home audio systems and headphones. (Note: Microphone is not supported). The RCA output can be connected to a desktop amplifier or powered speakers. The built-in Hi-Fi headphone amplifier chip can drive headphones from 16 ohms to 200 ohms. The Q4 headphone USB DAC features a Texas Instruments NE5532 high-performance operational amplifier chip that combines excellent DC and AC characteristics. It boasts extremely low noise, high output drive capability, high unity amplification, and maximum output swing bandwidth, low distortion, high slew rate, input protection diodes, and output short-circuit protection. This 160mW RMS (32 Ω, 20 Hz - 20 kHz, 0.01% THD) digital audio adapter features bass and treble controls and can be as a preamplifier or volume controller for PC/MAC/headphone/speaker systems. It's easy to set up and connect, requiring no separate software, apps, or drivers. This ultra-compact D/A converter features a full metal casing to guarantee high quality. It streams low-jitter, bit-perfect 24-bit/192kHz HD audio and includes output protection circuitry, making it safe for expensive audio systems. Shipping details: Q4 USB DAC x1, USB charging cable x1, optical cable x1, PC-USB to Type-B cable, user manual x1, 24-month warranty. If you have any questions about installing the product, please feel free to contact us. We will provide detailed guidance. If the Q4 is recognized when connected to your computer via USB, but the LED on the front panel does not light up, please check the following: First, turn the volume/power knob clockwise all the way until the power switch is securely turned ON. Also, connect the USB cable directly to a USB port on the back of your computer. Avoid using the front USB ports of your computer, bus-powered USB hubs (unpowered USB hubs), or USB ports where power supply may be limited. Note: PC-USB supports input sampling rate: 96K/24Bit, high/low audio adjustment range: ±6dB. Fiber/coaxial support input sampling rate: 192K/24Bit, frequency response: 20Hz-20kHz (±3dB). PC-USB supports operating systems: XP/W7/W8/W10/MAC/Linux. Distortion: 0.01%. Operating voltage: DC5V. Amplifier output maximum power: 100mW with 32Ω load. Signal-to-noise ratio: ≥105dB. Headphone matching impedance: 16-200Ω.