Fosi Audio SK02 DAC Headphone Amplifier for PC, Desktop Balanced DAC Amp

I picked up the Fosi Audio SK02 because my PC’s built-in audio was starting to feel limited, and I wanted a small desktop unit that could drive my headphones better while also handling optical input from my setup. The mix of USB-C, optical, 3.5mm, and 4.4mm balanced outputs looked practical for everyday use without taking up much space.Going in, I expected a clean-sounding DAC/amp that could push regular headphones and some planars without noise or strain, plus basic preamp use. It mostly delivered. The aluminum case feels solid and sits steady on the desk. The big volume knob is smooth, and the gain switch plus LEDs make it easy to see what’s going on. Plug in via USB-C or optical and it just works—no drivers needed on my end.Sound is neutral and clear. Bass stays tight, mids are open, and it has enough power on the balanced 4.4mm side to give harder-to-drive headphones some headroom. I use it for music and gaming, and the quieter background helps pick out details better than the motherboard jack. The line out also works fine if I want to feed a powered speaker or another amp.For daily desk use it’s handy—connect the PC or a TV via optical, switch headphones quickly, and keep the volume independent. Value feels solid for what you get in power and inputs at this price point.A few things keep it from being perfect. The treble can come across a bit linear or bright depending on the headphones. It always needs USB-C power, so it’s not fully portable. And there’s no app or fancy tuning options if you like tweaking on the fly.It met my main expectations for cleaner desktop audio and enough power without complications. Not the last word in refinement, but a practical step up from basic PC sound that does the job well.

Works great !! I connected it to my laptop via a USBc cable. I noticed an improvement in overall sound. I’m running it through a Fosi BT30D Pro. Makes for a cool, compact, and clean sounding desktop set up. I used Google to help with optimizing the processing settings. Would definitely buy again…. Well I would…. If I had another home office computer.

Although I returned this Fosi Audio SK02 DAC Amp Headphone Amplifier I am giving it 5 stars because for what it is and for it's price I think it's a good value and performed well for me while I was trying it out. One of the reasons I considered this product was because of the high headphone power output and inclusion of both single ended and balanced headphone outputs. The power was definitely sufficient to drive all the headphones I own (Sennheiser HD6XX, Sennheiser 560S, HiFiMan Edition XS, FiiO FT1, Grell OAE1) although I didn't try it with some vintage 600 Ohm headphones I own. However, I returned it because I really needed to be able to see the volume level that was set more clearly than what the small led light could indicate. That single light was too vague to know where in the scale the volume was set. I have opted to choose another product that has an led screen which can constant show the volume from 0 to 99 at all times. This may not be a consideration for other people however. I also liked the form factor and design which took up less space on my desktop than the other product I ended up selecting. So, in summary, I consider this a very good product that unfortunately just didn't meet my specific needs. If the lack of constant volume level indicator and led screen isn't an issue, then you would probably be happy with this DAC/Headphone Amp.

This desktop DAC/amp delivers pristine audio clarity and plenty of driving power through both its 3.5mm single-ended and 4.4mm balanced connections. The USB-C and optical inputs set up effortlessly with PCs and home audio systems, offering smooth volume control in a rock-solid, space-saving metal housing.

The Fosi Audio SK02 DAC amp is a compact, affordable option with a clean, neutral sound signature, making it ideal for detail-oriented listening. Powered by the ESS Sabre ES9038Q2M DAC, it offers clear audio with a slight emphasis on mid-to-high frequencies, which suits analytical listening but can be bright for sensitive ears. It includes both 3.5mm single-ended and 4.4mm balanced outputs, delivering up to 1100mW to power even demanding headphones. Its sturdy aluminum build, versatile connectivity, and intuitive volume control make it a practical choice for budget-conscious users​

I want to love this amp but it has two critical flaws. Fosi went with a digitally-stepped volume control, and like so many of these controls the difference in volume between steps is too high. My IEM volume is either too low or too high, and no step in between. My other Fosi amps don’t have this problem. The other flaw is that it does not respond to my Mac’s MIDI streaming controls that would allow me to reduce the sound. Good sound quality but I cannot use it for IEMs because the volume controls are too coarse. Which is a shame, because that such an easy problem to solve.

Excellent sound, and as a desktop DAC/Amp, this thing should be fed by a USB port with some real power capacity (or at least not a portable like a tablet or phone).They seem to be able to drive my 300Ω Sennheiser to dangerous volume levels without distortion. I'm not in the habit of listening at that kind of volume for very long.I don't hear any noise or distortion at any volume, in fact - the DAC & Amp are both excellent. The build quality appears top notch, though the case is clearly an area where some cost cutting happened (it's a bit of a generic case, but serviceable).The bottom of the case has some non-slip silicone pads integrated into it. I wish it covered the whole bottom, but it's still better than nothin'. It's also nice to have an optical in. I'm not sure if I'll ever use it, but options are good.I love being able to use the push knob to pause/play skip music, and even turn the SK02 off (rather than an always-on power sink).I bought mine with a package deal that was cheaper to get an Orange knob - I'm not entirely sold on the look, but it's certainly easier to find the knob.The SK02 a bigger amp than the diminutive Fosi DS2, and is definitely louder. It also has more features. I've got both, love both - they're different horses for different courses.

Works very well on a PC - I could not be happier for headphone listening on my PC. I use the USB input and 3.5mm headphone jack for the output. It installed perfectly on my Windows 11 PC, which recognized it right away. I don't really know if it installed any drivers, but it doesn't matter to me since it just works and sounds great. It's the best $90 I've spent on my audio/PC system. Highly recommended.

Very nice! I use this DAC as a external sound card for two computers, by plugging it into a USB hub into a KVM switch. It takes control of the volume output, so volume control for both the Windows and Linux machine is controlled with the dial. Tweaking the output volume in the Windows OS has no effect on the output volume, however on Linux the OS volume seems to control the gain a bit. But I just set the volume to something which sounds undistorted, and I got the same volume in both OSes. Don't notice delay in sound either. Music playback sounds great. Perfecto.

just received this morning, setup was easy, usb from P.C, which carries signal and 5v power, optical from TV used as monitor. Headphones sounded great whether from 4.4 mm balanced or from 3.5. I attached a 3.5 mm audio cable, from the aux out on rear of unit, to my active speakers and all good there too. Controls on top of unit for gain, high/low, a mode selector for optical or USB input, and a volume control knob, with an array of led lights to indicate bit rate and mode. Small yet solidly built. All the connections I need for desktop system are there and at a reasonable price.

Petit ampli casque qui est surprenant tellement il délivre un son puissant et cristalin.Associé à un ATH M50X, je trouve rien à redire.Qualité du boitier au top, il suffit de connecter en USB C de par et d'autre...à acheter les yeux fermés.

صراحه مره خرافي و كل شي فيه تمام و يشغل سماعات ثقيله يعني كويس بس فيه مشكله اتوقع انها من المدخل اذا رفعت الصوت اخر شي يفصل الجهاز اتوقع انها من المدخل بس انها مشكله واجهتني

Absolutely loved the sound, sadly the headphones i needed the amp to drive weren't balanced, and the 3.5mm didn't have enough juice to drive them so i had to return them in favour of of the 01 amp, it was 100% a downgrade and the 02 were only 100 (~€10) sek more at the time but i didn't have much choice, if it can only drive balanced headphones then i can't use it. I'm even considering getting these again to use it as a dac for the 01 (and potential balanced headphones in the future).