- High-performance desktop DAC and headphone amplifier with ESS ES9038Q2M DAC chip for superior audio decoding up to PCM 32-bit/384kHz and DSD256.
- Powerful amplification delivering up to 1100mW at 32 ohms via balanced 4.4mm output, suitable for headphones and IEMs from 16 to 300 ohms.
- Multiple inputs including USB Type-C and optical Toslink, with outputs for 3.5mm single-ended, 4.4mm balanced headphones, 3.5mm line out, and optical pass-through.
- Ultra-low distortion with THD less than or equal to 0.001% at 1kHz and high signal-to-noise ratio up to 120dB for crystal-clear sound.
- Plug-and-play design with no drivers required, featuring a multi-functional knob for volume, power, and playback control.
- High and low gain modes with quick-switch buttons and colorful LED indicators for sampling rate and operational status.
- Versatile connectivity for computers, laptops, CD players, TVs, and projectors, doubling as a preamp for active or passive speakers.
- Durable aluminum alloy construction via CNC machining, compact size for desktop use, and backed by a 24-month warranty.
Product Overview
The Fosi Audio SK02 is a compact desktop DAC and headphone amplifier that combines high-resolution audio decoding with powerful amplification in a sleek, user-friendly package. Designed for audiophiles and casual listeners alike, it supports advanced formats like PCM up to 32-bit/384kHz and DSD256 through its USB input, while the optical input handles up to 24-bit/192kHz. With dual headphone outputs—3.5mm single-ended and 4.4mm balanced—the SK02 caters to a wide range of headphones and in-ear monitors, delivering robust power to drive even demanding loads. Its plug-and-play functionality eliminates the need for drivers, making it compatible with Windows, Mac, and other devices right out of the box. Whether you're upgrading your desktop audio setup, connecting to a TV for better sound, or using it as a preamp in a home theater system, the SK02 provides an affordable yet high-performing solution that enhances every listening session with detailed, immersive sound.
Superior Audio Decoding and Processing
At the heart of the Fosi Audio SK02 lies the premium ESS SABRE ES9038Q2M DAC chip, renowned for its precision and ability to handle high-resolution audio files with exceptional fidelity. This chip ensures accurate digital-to-analog conversion, supporting PCM formats up to 32-bit/384kHz and native DSD256 playback via USB, allowing you to experience music as the artist intended with minimal jitter and artifacts. The optical input complements this by accepting signals up to 24-bit/192kHz, ideal for connecting to sources like CD players or gaming consoles. Paired with high-quality SGM8262 operational amplifiers, the SK02 achieves an ultra-low total harmonic distortion (THD) of ≤0.001% at 1kHz and a frequency response of 20Hz-20kHz with ±0.02dB deviation, preserving the full spectrum of sound from deep lows to crisp highs. This setup results in a noise floor as low as 3.7μV, ensuring that subtle details in recordings emerge without background interference, making it a top choice for critical listening and high-fidelity audio enthusiasts.
Powerful and Versatile Amplification
The SK02's amplification stage is engineered to provide ample power for a variety of headphones, featuring high and low gain modes to match different sensitivities and impedances ranging from 16 to 300 ohms. Through the 4.4mm balanced output, it delivers up to 1100mW at 32 ohms in high gain mode, dropping to 550mW at 64 ohms, 150mW at 250 ohms, and 120mW at 300 ohms, while low gain offers 350mW at 32 ohms, 180mW at 64 ohms, 50mW at 250 ohms, and 40mW at 300 ohms. The 3.5mm single-ended output provides 280mW at 32 ohms in high gain, scaling down accordingly. This power ensures dynamic headroom for explosive transients and sustained volume without distortion, enhancing the soundstage and separation in balanced mode. The inclusion of a 3.5mm line output allows the SK02 to function as a preamp, connecting to external amplifiers or powered speakers, expanding its utility beyond personal listening to full home audio systems.
User-Friendly Features and Controls
Ease of use is a hallmark of the Fosi Audio SK02, with a large multi-functional knob that handles power on/off, volume adjustments, and even play/pause functionality for seamless control. Dedicated buttons allow quick switching between high and low gain modes as well as input sources, while colorful LED indicators provide at-a-glance information on the current sampling rate and operational status—red for standard rates, blue for high-res, and purple for DSD. This intuitive interface eliminates complexity, making it accessible for beginners while satisfying advanced users. Powered solely by a 5V USB Type-C connection, the SK02 draws minimal energy and operates without overheating, ensuring reliable performance during long sessions. Its optical pass-through output further adds convenience, allowing daisy-chaining to other devices without signal loss.
Wide Compatibility and Connectivity
The Fosi Audio SK02 excels in versatility, offering USB Type-C and optical Toslink inputs for broad compatibility with modern devices. Connect it to computers or laptops for an instant audio upgrade, or link it to TVs, projectors, and CD players via optical for enhanced media playback. It serves as an external sound card, bypassing inferior built-in audio hardware to deliver superior quality for music, movies, and games. While it supports high-resolution formats on USB, the optical input ensures stable connections for standard hi-fi sources. Additionally, the SK02 can integrate into larger setups by outputting to amplifiers like the Fosi Audio V3 or ZA3, making it a flexible component for both desktop and home theater environments. No additional software is needed, ensuring hassle-free setup across Windows, Mac, and other platforms.
Build Quality and Durability
Crafted from a single piece of aluminum alloy using precision CNC machining and sandblasting, the Fosi Audio SK02 boasts a premium, durable build that withstands daily use while maintaining an elegant appearance. Measuring just 4.76 x 2 x 1.69 inches and weighing 0.84 pounds, its compact footprint fits neatly on any desk or shelf without clutter. The robust construction provides excellent heat dissipation and protection against impacts, ensuring longevity. Secure connectors for all inputs and outputs minimize wear over time, and the overall design prioritizes both aesthetics and functionality. With a 24-month warranty and dedicated customer support, the SK02 offers reassurance that your investment in high-quality audio is protected, making it a reliable choice for long-term enjoyment.
Specifications
- Model: SK02
- DAC Chip: ES9038Q2M
- Operational Amplifiers: SGM8262
- Inputs: USB Type-C, Optical Toslink
- Outputs: 3.5mm Headphone (Single-Ended), 4.4mm Headphone (Balanced), 3.5mm Line Out, Optical Pass-Through
- Supported Formats (USB): PCM up to 32-bit/384kHz, DSD256
- Supported Formats (Optical): Up to 24-bit/192kHz
- Output Power (3.5mm High Gain): 280mW @ 32Ω, 130mW @ 64Ω, 40mW @ 250Ω, 30mW @ 300Ω
- Output Power (3.5mm Low Gain): 90mW @ 32Ω, 50mW @ 64Ω, 15mW @ 250Ω, 10mW @ 300Ω
- Output Power (4.4mm High Gain): 1100mW @ 32Ω, 550mW @ 64Ω, 150mW @ 250Ω, 120mW @ 300Ω
- Output Power (4.4mm Low Gain): 350mW @ 32Ω, 180mW @ 64Ω, 50mW @ 250Ω, 40mW @ 300Ω
- Frequency Response: 20Hz-20kHz (±0.02dB)
- Total Harmonic Distortion (THD): ≤0.001% @ 1kHz
- Signal-to-Noise Ratio (SNR, 3.5mm): 116dB (Low Gain), 120dB (High Gain)
- Signal-to-Noise Ratio (SNR, 4.4mm): 110dB (Low Gain), 115dB (High Gain)
- Noise Floor: 3.7μV
- Recommended Headphone Impedance: 16-300Ω
- Power Supply: 5V USB Type-C
- Dimensions: 4.76 x 2 x 1.69 inches (121 x 51 x 43mm)
- Weight: 0.84 lb (380g)