Fosi Audio SK02 Audio Amplifier USB Decoder Support DSD 256 PCM DAC Headphone Amp for 3.5MM & 4.4MM Balanced Headphone - AliExpress.io

Specifications

Brand Name

Output Type

OPTICAL, LINE OUT (AUDIO OUT), Balanced Out

Built-in Battery

Yes

Recommended Headphone Maximum Impedance

251 - 300 Ohm

Input Type

USB, OPTICAL

High-concerned chemical

None

DSD (Direct Stream Digital)

Yes

Body Material

aluminum

Dimensions (WxHxD)

121*51*43mm

Channels

2 (2.0)

Signal To Noise Ratio

3.5mm:120dB 4.4mm:115dB

Bluetooth

Type

Mini Amplifier

WIFI

Model Number

SK02

Output Voltage

3.5MM:280mW/32ohm 4.4MM:1100mW/32ohm

Package

YES

Certification

CE, FCC

Origin

Mainland China

PCM

Yes

DAC Model

ES9038Q2M

Brand

Fosi Audio

Input

USB, OPT

Output

3.5/4.4mm Headphone Jack, 3.5mm AUX/OPT

SNR 3.5mm Headphone Jack

Low Gain: 116dB High Gain: 120dB

SNR 4.4mm Headphone Jack

Low Gain: 110dB High Gain: 116dB

Distortion

≤0.001% @ 1kHz

Background Noise

3.5mm Headphone Jack: 3.7μV 4.4mm Headphone Jack: 12μV

Headphone Impedance

16-300Ω

Input Voltage

DC 5V

feature

Portable headphone amp,Desktop headphone amp,USB DAC

frequency response

20Hz-20kHz(±0.02dB)

Product Description

Fosi Audio SK02 DAC Headphone Amplifier Preamp Support DSD 256 PCM For 3.5MM & 4.4MM Balanced Headphone

Features:

*Compact Yet Powerful: The SK02 employs a minimalist and stylish design language. Despite its small size, it boasts mighty features. It supports DSD256 and PCM 32bit/384kHz high-resolution decoding, along with 3.5mm single-ended and 4.4mm balanced headphone outputs. Its robust power can easily drive wide range of headphones and IEMs with an impedance range of 16-300 ohms.

*Stunning Performance: It features a high-end ESS SABRE ES9038Q2M DAC and SGM8262 op-amps. Its excellent circuit design ensures superior parameters with a SNR as high as 120dB, a low noise floor of only 3.7μV, and an incredibly low THD of 0.001%. The 4.4mm balanced output power reaches an impressive 1100mW at 32 ohms. The exceptional high-resolution capability and pure sound quality make every listening experience an extraordinary sensory journey.

*User-Friendly Design: The SK02 requires no drivers and offers plug-and-play convenience. It integrates a big multi-functional control knob, allowing easy access to power on/off, play/pause, and volume adjustments. The unit features quick-switch buttons for high/low gain and input modes. Additionally, its colorful indicator lights enable effortless identification of the current working mode and the song's sampling rate.

*Remarkable Versatility: Supports USB and optical input, widely applicable for decoding with computers, laptops, CD players, TVs, and projectors. Not only can it function as a headphone amplifier, but it can also serve as a preamp, pairing with active speakers or an amplifier like Fosi Audio V3, ZA3, TB10D amp and passive speakers to form a desktop listening or home audio system.

*Exquisite and Durable: The SK02 is crafted from a single piece of aluminum alloy using CNC machining and a delicate sandblasting process. This not only gives it an exquisite appearance but also ensures lasting durability. In addition, Fosi Audio pledges to provide a 24-month worry-free warranty and responsive customer service to all users.

Highlight:

Model: SK02
Input : USB/OPT
Output : 3.5mm Headphone, 4.4mm Headphone, 3.5MM line out/OPT
Powe Supply:5V
Power Input Interface: USB Type-C
THD≤0.001% @ 1kHz
SNR:

3.5mm Headphone: Low Gain:116dB High Gain:120dB

4.4mm Headphone: Low Gain:110dB High Gain:115dB

Frequency response: 20Hz-20kHz (±0.02dB)
Amp output maximum power:

3.5MM：High Gain: 280mW@32Ω, 130mW@64Ω, 40mW@250Ω, 30mW@300Ω

Low Gain: 90mW@32Ω, 50mW@64Ω, 15mW@250Ω, 10mW@300Ω

4.4MM：High Gain: 1100mW@32Ω, 550mW@64Ω, 150mW@250Ω, 120mW@300Ω

Low Gain: 350mW@32Ω, 180mW@64Ω, 50mW@250Ω, 40mW@300Ω

Headphone matching impedance: 16-300Ω
PC-USB Sampling Rate: 32Bit/384KHz DSD256
OPT Sampling Rate: 24Bit/192KHz
DAC Chip: ES9038Q2M
Size (L*W*H): 4.76*2*1.69inch (121*51*43mm)
Net Weight: 0.84lb/380g

Package Include:

*1x Fosi Audio Sk02 Headphone Amp
*1x 2-in-1 USB Type-A/C to Type-C Cable
*1x User’s Manual

Pros & Cons

Pros

Compact, minimalist aluminum design that fits easily on desktop setups or travels well
Supports high-resolution audio formats including DSD256 and PCM 32bit/384kHz for crisp, detailed sound
Offers both 3.5mm single-ended and 4.4mm balanced headphone outputs to accommodate different headphone types
Low distortion levels (≤0.001% @ 1kHz) and high signal-to-noise ratios for minimal background noise and clear audio playback

Cons

No built-in Bluetooth or Wi-Fi connectivity, so wireless audio streaming is not supported directly through the unit
Only includes USB and OPTICAL input ports, limiting your available audio source options compared to competing models with RCA or XLR inputs
The required DC 5V power adapter is not included in the standard package, so you will need to source one separately to use the amplifier
The 4.4mm balanced output has a slightly lower signal-to-noise ratio than the 3.5mm output, which may be noticeable with high-sensitivity headphones

Common Questions

What material is the Fosi Audio SK02 amplifier body made from?

The amplifier's body is constructed from aluminum, as specified in the product specifications.

What are the dimensions of this compact audio amplifier?

The unit measures 121*51*43mm, per the listed product details.

Which input and output devices is this amplifier compatible with?

It supports USB and OPTICAL inputs, and provides 3.5mm single-ended and 4.4mm balanced headphone outputs, plus line out audio ports.

What key audio formats does this DAC amplifier support?

It supports DSD 256 and PCM 32bit/384kHz high-resolution audio formats, as noted in the product description and specs.

What is the country of origin for this Fosi Audio SK02 amplifier, and does it include certifications?

This product is manufactured in Mainland China, and it holds CE and FCC certifications, per the product specifications.