Main chip: HIFI-level PCM2704 USB decoder chip. Performance is comparable to entry-level market chips such as the CM102S series. Powered via USB. Analog output can be directly connected to headphones. Also provides SPDIF digital output for use with advanced external DACs to enhance audio quality. As an external sound card, its design helps reduce electromagnetic interference, improving signal-to-noise ratio and overall sound quality. PCM2704 is a monolithic digital-to-analog converter (DAC) chip featuring two DAC output channels and an integrated USB interface controller. Compliant with USB 1.1 standard. Supports audio input sampling rates of 32 kHz, 44.1 kHz, and 48 kHz, with 16-bit stereo or mono data. Includes on-chip volume control and mute functionality, synchronized with computer settings. USB-powered — simply plug into a computer’s USB port; no additional power source required. Supports 16-bit audio at 32 kHz / 44.1 kHz / 48 kHz. Supports 2-channel analog output and S/PDIF digital output. Dynamic range / signal-to-noise ratio: 98 dB. Total harmonic distortion + noise (THD+N): 0.006% (load = 10 kΩ); 0.025% (load = 32 Ω). USB interface complies with USB 1.0 specification. Compatible with Windows XP, Windows 7, and Windows 2000 (driver-free). Windows 98SE requires driver installation. Dimensions: 55 × 50 mm. PCM2704 Specifications: Operating voltage: 5 V (via USB interface). THD+N: 0.006% (RL = 10 kΩ); 0.025% (RL = 32 Ω). Signal-to-noise ratio: 98 dB. Dynamic range: 98 dB. Headphone output power: 12 mW (RL = 32 Ω). Color: As shown. Material: Polycarbonate (PC). Package includes: 1 × PCM2704 USB-powered sound card decoding module. Note: Color appearance may vary slightly due to lighting conditions and display settings. Measurement tolerance: ±1–3 cm.