The Fosi SK02 shows itself as a pretty compact desktop DAC/AMP, ideal for space conscious users. But I can tell you that its desktop aesthetic offers remarkable versatility and it makes it suitable for mobile use as well!
The metal housing feels like a metal brick, and it fits greatly into any desktop setup or on the go powerful audio rig and its is available for $99.
Disclaimer:
I have to note that this review unit of the Fosi SK02 was provided to me directly by Fosi Audio. I appreciate their support but I want to keep it clear that all opinions expressed in this review are my own and based on my independent testing and experience! I want to keep my reviews unbiased and transparent as much as possible and offer an honest perspective for potential buyers.
Unboxing
The Fosi SK02 arrived in a minimalist box with the phrase ‘HiFi Made Fun’ written on it, and it sets the tone for what was inside. Upon opening the Fosi SK02 box, the sleek metal device was revealed and it was concealed in protective foam.
Additionally, I found a user manual and a USB Type C to Type C cable with a USB Type A to Type C adapter which makes it suitable for various devices!
Design and Build Quality
The SK02’s design stands out from the crowd, taking minimal desk space and making it easy to carry with you when you are on the go. Although you may not be able to put it in your pocket… It is still small enough to easily fit in your bag. I personally love its visual appearance, it may not appeal to everyone’s aesthetic preferences…
The large volume knob doubles as a power button and play/pause control and it offers a convenient operation. However, it has a very lightweight feel and I can easily make accidental adjustments… Additionally, the volume level light indicator is very inconvenient to use, as it shows the volume level by its changing flashing brightness, and the absence of an LCD display makes checking volume levels slightly harder.
Technical Specifications
- DAC Chip: ESS Sabre ES9038Q2M
- Operational Amplifier: SGM8262
- Maximum Sample Rate: PCM 384kHz/32bit, DSD256
- Input: USB Type-C, SPDIF (shared)
- Output: 3.5mm single-ended, 4.4mm balanced (high gain 32Ω: 280mW/3.5mm, 1100mW/4.4mm / low gain 32Ω: 90mW/3.5mm, 350mW/4.4mm)
- SNR: 3.5mm – Low Gain 116dB / High Gain 120dB. 4.4mm – Low Gain 110dB / High Gain 115dB
- Distortion: ≤0.001% @1kHz
- Noise Floor: 3.5mm – 3.7μV / 4.4mm – 12μV
- Crosstalk: 3.5mm – Low Gain 128dB / High Gain 137dB. 4.4mm – Low Gain 112dB / High Gain 110dB
- Frequency response: 20Hz-20kHz (±0.02dB)
- Headphone impedance: 16-300Ω
- Input voltage: DC 5V
- Hardware Controls: Power, volume, high/low gain switching, input switching
- Dimensions: 130mm (H) x 62mm (W) x 23mm (D)
- Weight: 340g
Versatility and Connectivity
I think that the Fosi SK02 really stands out for how versatile it is and all the different ways you can connect it to your audio setup. One of the best features, I noticed immediately is that it can be powered with only my phone and it makes it portable and somewhat possible for carry around and I find this feature very welcome!
The SK02 gives you a few options to connect it to different audio sources and devices. It offers a standard 3.5mm headphone jack, a 4.4mm balanced output and an additional 3.5mm AUX output on the back, which from my testing has lower power output and probably can act as a preamp.
The optical input on the SK02 also gives you the option to connect digital audio sources like PCs, consoles, or TVs. And for me all of this makes the SK02 super versatile and easy to fit into pretty much any audio setup!
On top of that, the Fosi SK02 has an SPDIF output from the back 3.5mm optical output. This dual feature really gives you even more options for connectivity and it lets you use the optical output for digital audio as an “adapter” or the regular AUX output.
so… all in all, the Fosi SK02 is great for its versatility and all the ways you can connect it. Whether you’re an audiophile, music lover, or just a casual listener, the SK02 is an awesome audio companion! And what made me really fall in love with it is the fact that It works as a portable headphone amp or as part of a home audio system.
Controls and User Experience
The SK02 prioritizes user convenience with intuitive controls and clear indicators. The volume knob, despite its lightweight feel, offers very precise volume adjustments with big number of volume levels. Additionally, a single button switches between the low and high gain and is shown by LED lights. It gives users the option to optimize the setup to their headphone/IEM requirements.
Further enhancing versatility, the SK02 conveniently allows you to switch between optical and USB input sources at the press of a dedicated button. This flexibility caters to various connection preferences and seamlessly integrates the SK02 into different setups, be it your computer, mobile phone, or a dedicated media source with optical output or even an optical input.
Additionally, there is a sampling rate indicator and it goes from 44.1kHz to 384kHz, and a DSD indicator from 64 to 256. However, the flashing and volume indicator, while attempting to convey loudness levels, may prove distracting and less informative in practice, And I must say… it really annoys me…
Power
The Fosi SK02’s multiple output options makes it so it can fit in many audio setups. its 3.5mm single ended output on the front panel delivers 280mW (on high gain) clean and detailed sound. This output provides pretty much enough power to drive most IEMs and headphones efficiently.
In addition to the 3.5mm single ended output, the SK02 also offers a 4.4mm balanced output on the front panel and this one brings 1100mW (on high gain)!. I should note that the balanced output is offering several advantages, which are, improved channel separation, reduced crosstalk and lower distortion compared to single ended connections… It gives a more powerful dynamic and also can drive even more power hungry headphones and even planar headphones.
Furthermore, the SK02 offers a rear 3.5mm AUX output, giving users with added flexibility in their audio setups. While this rear output delivers less power compared to the front 3.5mm output, it still offers sufficient amplification to drive a wide range of IEMs with ease. But in my case, I was using it as s preamp…
Sound Performance
The Fosi SK02 brings a sound signature which more bright and detailed, and showing itself as a more revealing performer. At its core is the ESS Sabre ES9038Q2M DAC chip, which is actually known for its clean and crisp sound delivery… This gives the SK02’s its most defining characteristic, which a pronounced mid-treble focus.
This focus gives sparkly sound to cymbals, airy vocals, and great details for string instruments. The SK02 excels at showing micro details and to my taste it is inviting to delve deep into the music with analytical approach! But I should warn you that this focus can become a double edged sword… Harsh recordings or tracks heavy on high frequency content might sound overly bright or even piercing to sensitive ears…
Vocals have their own space, delivered with clarity and precision! Every word carries weight and offering a transparent window into the artist’s expression. However, this analytical presentation can come at the cost of the warmth and fullness that you might get with the traditional “musical” midrange… Instruments like guitars and brass instruments may lack the organic body and richness found in warmer amps…
Bass presence keeps itself solid, controlled, and tight and proves a good foundation for the rest of the spectrum. It brings enough punch to satisfy most genres but doesn’t overpower the mids and highs. However, bassheads or those seeking a more impactful low end rumble might find it wanting compared to warmer competitors like the Truthear Shio…
But overall, I find the Fosi SK02 great for those analytical listeners who prioritize detail and clarity. It shines with acoustic and classical music, where its ability to unveil intricate details is a strength. However, its bright focus might not be for everyone… Especially those who prefer a warmer, more forgiving sound…
Conclusion
So, after all of this, I can easily say that the Fosi SK02 stands out as a versatile DAC/AMP that transcends its desktop oriented design to offer mobile users a compact and powerful audio solution with the possibility to run only on a single USB! Yes, it has a bright and detailed sound signature, and may not be ideal for bassheads, but its sturdy build quality, and diverse connectivity options makes the SK02 a great option for audiophiles seeking a balance between portability and performance. And while this one can feel a little like a brick… it does little to diminish the overall value as a versatile and capable audio on the go companion for both desktop and mobile use. And lets not forget that all this package is priced at $99… And it makes it a great all arounder for those who want it to do everything on a limited budget!
Pros:
- Good build quality and visually distinct vertical design.
- Clear, detailed, and analytical sound signature.
- Versatile connectivity options with USB-C, SPDIF IN/OUT, and rear AUX out.
- Powerful output, especially through the balanced 4.4mm jack, suitable for demanding headphones.
- Large volume knob with multiple functions (power, play/pause).
- Easy to use with no complex setup.
- Sampling rate indicator lights.
Cons:
- Lightweight and easily adjustable volume knob, prone to accidental changes.
- Inconvenient volume-level light indicator.
- Brighter sound signature with emphasis on mids and highs, potentially fatiguing for some.
- Kind of brick bulky…
Where to buy:
Amazon US
Aliexpress
Promo code: FASKMKT15 (expired on 31st, March)