Fosi Audio SK01 | Headphone Amplifier and Preamp

The Fosi Audio SK01 is a Powerful Headphone Amp, a Customizable Analog Preamp, and An Accurate Equalizer, All-in-One Portable Device

• Integrated treble, middle, and bass controls with midpoint positioning
• Abundant interfaces and adjustments for personalized sound output
• Caters to both desktop and portable music listening
• Up to 6 hours of continuous usage with built-in high-capacity battery

Tailor-Made Audio Experience

The Fosi Audio SK01 is a versatile headphone amplifier designed for both desktop and portable setups, offering powerful amplification and precise tone shaping. With its tri-band EQ for treble, mids, and bass, you can tailor your sound to suit your personal preferences.

Whether used as a high-performance headphone amp, an adjustable analog preamp, or a detailed equalizer, the SK01 enhances your listening experience with refined sound and customizable character.

As a headphone amp, it enhances your listening with added depth and clarity. As a preamp, it delivers clean, powerful signal amplification. And as an equalizer, it fine-tunes your sound with precise control, revealing the full detail of every instrument.

Unmatched Headphone Compatibility

Unlock powerful performance and flexible connectivity with the Fosi Audio SK01. Featuring a 3.5mm line-in, 3.5mm line-out, and a combined 3.5mm/6.35mm headphone output, the SK01 adapts to your setup with ease. With up to 2400mW RMS output at 32Ω and support for headphone impedances ranging from 16–300Ω, it delivers dynamic, high-quality sound in a compact and portable form, perfect for elevating any listening environment.

Additional Features

Long-Lasting Battery
Enjoy up to 6 hours of continuous usage with the built-in high-capacity battery, while the isolated power design rejects interference, providing a pure listening experience without any interruptions.

Exquisite Design
Crafted with an aluminum alloy body, the SK01 is both elegant in appearance and touch, adding a touch of sophistication to your desktop setup.

Tri-Band Control
With independent treble, midrange, and bass controls—plus central detents for tone bypass—dialing in the perfect balance is effortless. In high-impedance mode, the SK01 delivers up to 2400mW of powerful output.

Diverse Capabilities
Quickly restore the original sound with a single press of the tone-defeat button. Enjoy immersive late-night listening with the loudness function, and fine-tune output for different headphones using the adjustable gain switch.

Specifications

• Input: 3.5mm line-in
• Output: 3.5mm headphone, 6.35mm headphone, 3.5mm line-out
• Amp Output Max. Power
  • High Gain: RMS 2400mw/ 32Ω
  • Low Gain: RMS 300mw/32Ω
• Frequency Range: 20Hz-20kHz (±0.5dB)
  
• THD+N: 0.001% @ 1kHz and 770mV
  
• SNR: ≥108dB
  
• Headphone Matching Impedance: 16-300Ω
  
• Dimensions: 4.76" x 2" x 1.69"
  
• Weight: 0.641b
• Power Supply: 5V, USB Type-C

In the Box

• Fosi Audio SK01 Amplifier and preamp
• USB-A/C to USB-C cable
• User manual