Fosi Audio K5 Pro DAC Amp Headphone Amplifier, Mini Hifi Stereo Digital-to-Analog Converter, USB Type-C/Coaxial/Optical to 3.5MM AUX/RCA Jack, for Gaming PS5/ PC/Active Speakers Up to 24 bit/192 kHz

As a daily driver of the Fosi Q4 DAC (in combination with the BT30D amp) for my computer, and a BT20D for the bedroom it's safe to say I like Fosi gear. The K5 Pro is a fantastic upgrade and replacement for the Q4 in several aspects. 1. Build quality and design: the new design of Fosi products has made the old black boxes look more sleek and modern. The gunmetal grey is stylish and works with any mini hifi setup or room. It just so happens to match the metal in my headphones and stand. 2. Connectivity: the Q4 used a 5v micro usb for power, then a full-size usb type B to connect to a pc (the optical and coaxial are the same on both models). With the K5, one usb c is used for both power and signal. What impressed me is the lack of interference when using the same cable for both. Initially I was skeptical of this (without cutting the cable to see) but I can assume that there is a good degree of shielding of the individual cores to prevent any interference or cross talk. In addition the K5 Pro has added a 3.5mm microphone input next to the 3.5mm headphone output. This output can power headphones from 16 ohm to 300 ohm. This is a 100ohm improvement over the Q4 and as I have a pair of HD660s it makes a lot of difference. Just like the Q4 there is a RCA output to connect to speakers or a seperate amp unit. 3. The DAC chip: the K5 Pro uses the new Texas Instruments NE5532 op-amp chip. Especially noticeable through headphones there is precise and punchy bass control and incredibly clear highs while never muddling the mids. 4. Gaming: both the K5 and Q4 are advertised as gaming DACs. The K5 really improves over the Q4 because of the NE5532 chip. Using Dolby Atmos for headphones the positioning and soundstage was perfect for FPS gaming and immersion. I have only one gripe about the K5 Pro. It's the power button. To turn on and off you have to long press the volume knob. This means every time the K5 loses power you have to turn it back on manually. The Q4 had a point on the volume where as you turn the volume up the DAC turns on. Once left at a volume the Q4 just turns on and off without having to touch it. It is all down to my laziness but the quick press of the volume to change the input is a very nice to have. In summary the K5 is a clear upgrade over my Q4. Comparing my review to others they are saying similar things. If you just want something that sounds great and incredibly portable to power your headphones or to connect to your active speakers the K5 is a no brainer for the price. If you want the best of both worlds by using a pair of headphones and passive speakers like me the price is a steal and leaves plenty of budget for an amp.

Arrived today, setup was incredibly easy was listening to superb sound quality within minutes! Box feels solid and dials have a nice stiffness with a very subtle tactile top centre mark. Lovely LED on the front is incredibly bright- enough to distract while gaming- I use an old slot cover to block it...

Good DAC that adds noticeable sound quality to high impedance headphones. A definite improvement over the motherboard sound card. easy to install, it is literally plug and play and gives good on the fly adjustment to volume & bass. This sits on my desk so is conveniently placed and it is powered by the PC so no external power is needed. Sound clarity is great and there is very little in the way of white noise when using at high volumes. I have found that now I have switched to In Ear Monitors, I don't need the benefits this DAC gives, but this is due to the low impedance of that style of headphone and not the K5. with IEMS I can't get anywhere close to max volume without a substantial amount of blood loss! If you are a true audiophile the K5 may be lacking in features but it is perfect for its advertised use case of gaming and I can absolutely hear the change in audio quality and clarity. directional sound is excellent and really adds to the gaming experience. A bonus was that it shipped with a headphone/microphone splitter cable for those using combined single cables.

This little amp is a quality product, it arrives well packaged in a smart box with simple instructions and a selection of leads. The leads themselves felt a little bit on the cheap side but perfectly good for the task, I suspect most audiophiles would buy their own leads anyway. The amp itself feels very solid, with an all metal case (no cheap plastic here) that has a nice satin finish, it isn't going to win any style awards with its functional looks, but still manages to convey a pleasing aesthetic that isn't going to look out of place in any setup. The amp was very easy to install and setup, literally plug and play on my PC with no fussy drivers to worry about. It all worked straight out of the box, and it worked very well indeed! The sound is great, with no noise and very clear highs and lows. My onboard sound is pretty decent on my MSI X470 Pro, but I would compare it to the difference between listening to an MP3 and then a FLAC of the same song. Like night and day! Overall this feels like a quality product that punches above its weight in all regards, I was so impressed I immediately bought another one for a family member who appreciates good audio. I don't think you can go wrong at this price point.

It's fine for the price, quality is ok. It measures distortions on the output but most people won't hear them in practice and it's relatively cheap. It can drive hifiman edition Xs just fine (which is often not that easy to drive properly), volume is plenty. However, because it has just analogue potentiometers on the front, they have a bit flimsy feeling and it's easy to get channel volume imbalance (that's for all devices with analogue knobs though), which then kills completely positioning in games - which is why I've returned mine and got instead dac with digital encoder knob for the volume, as that has no such issues with channel imbalance. There is also issue that on each power on of the computer I have to turn on the dac manually as well, as it powers off with the computer but doesn't come back on automatically. There are few other small but annoying things like that with this device, so have a think if that's something that wouldn't bother you in daily use. If not, then it's best one you can get for the price, otherwise look for something else - you can get great ones for just over a £100.

OK Hands up...although I'm a serious music-lover (hence "MusicMan"...) I am also a serious Gadget Geek and when I saw this little beauty on Amazon I just had to have one - especially as I already have the Fosi Audio DAC-Q4 and being delighted with it.... Out of the box I am immediately impressed with the quality of the K5 PRO, it feels and looks gorgeous.....silvery brushed aluminium....also included are three cables, a USB data transfer/power cable, a splitter cable to separate the mic. and headphone inputs and an optical (Toslink) cable. I get the unit connected firstly to my computer and power up the K5 PRO, a 3-second press on the right-hand MODE/VOL knob and there is a reassuring "click" as a relay closes internally and the left hand statue LED illuminates to (by default) USB input. (Each subsequent press moves the input to the next input selection). Worth mentioning here that this K5 PRO only requires one cable connection to my PC for power and data transfer whereas my older Q4 need 2 cables, one for power and a second for data transfer.....a bit cumbersome and the K5 PRO is much better in this respect.... I must confess to not being particularly a gamer, I found the K5 very satisfactory and it worked very well....someone else with more experience in this area might like to add comments....meanwhile I will concentrate on the Audio quality on all the inputs on the K5PRO. USB PC CONNECTION. No problem with the PC recognizing the K5 PRO..... With the Bass and Treble control set at 12 O'clock I cue up one of my favourite songs, WAV of Emmylou Harris "Kern River" and immediately here a very clean, clear sound, crisp mids and highs and good firm Bass line.....next a 24/192 Hi Res of Roger Waters "The Bravery of being Out of Range".....again impressive good clean sound. (By the way I use Audio Technica ATH-WD900 cans plus a pair of OneOdio ones as well....both sounded excellent. I decide, out of interest, to compare this K5 PRO with my older Q4 (see the 5th picture for size comparison)......first thing I notice is an improvement is the Bass response of the K5 PRO, slightly less "lumpy" and also the mid-range on the K5 PRO is cleaner and a little more "forward in the mix" compared with the Q4....a smoother frequency response. All in all a really good start for the K5 PRO....let's move on to .... OPTICAL DIGITAL INPUT I particularly love watching Music videos on TV so I connect the K5 PRO to my TV via the Toslink cable and play Pink Floyd "P.U.L.S.E. "Comfortably Numb".....superb!! After detecting a very slight latency, easily cured by adjusting my TV sound setting, I thoroughly enjoy this great recording....top marks here....moving on to the S/PDIF input... S/PDIF COAX INPUT I connect my FiiO M15S S/PDIF on the 3.5mm output to the coax input on the K5 PRO and run a Hi-RES 24/96 recording of Eagles "Hotel California" and I'm immediately in the groove man!! again, top marks. By the way at all times the e.q. settings are at 12 O'clock and tests show these work very well with improvements in treble being handy on older "duller" mp3 files...I have a few at 256mbps.... IN SUMMARY Can I recommend this Fosi Audio K5 PRO device?? You bet, Any improvements??....yes perhaps a 4.4mm balanced headphone out would be nice and I found the indents on the e.q. controls not always easy to see and I would like to have a slightly larger volume control knob like on the Q4....but really I am splitting hairs as this is a really good little DAC with excellent sound quality. Highly recommended and I hope this helps you.

Sound quality wise was ok, but USB interface died literally 31 days after purchase (24/07/25-25/08/25) so can’t return and so not much use to me now with only optical / coax inputs working. Doesn’t even make a good paper weight.

Another good and cheap Fosi DAC. I have few and they are definitely worth it