K5 Pro Mini Stereo Gaming DAC and Headphone Amplifier is, well, is a Gaming DAC and headphone amplifier from the Chinese hi-fi equipment manufacturer Fosi Audio. Price varies from place to place but it is safe to say that you can buy it for less than 80$ from their website, AliExpress, and a few other vendors.
Pros
- Decent power output
- Great tuning for competitive gaming
- Low noise floor
- Great Value
- Fun and useful tone controls
- Good ADC
Cons
- Limited to 24 bit / 96 kHz
- Not linear
- Internal DAC is mediocre and not very resolving
- Lack of microphone gain control
- No spatial audio solution is included
Disclaimers
Without boring you too much, I don’t necessarily have a sound preference. I tend to enjoy different sound profiles as long as they do well at what they intend to do. I try to be critic in my reviews but I might be somewhat biased one way or another (Freebies, Recency bias, buyer’s bias etc.). Please keep these in mind. Also, K5 Pro Gaming DAC/Amp is provided to us by Fosi Audio, so we thank them. I will try to be as objective as I can, but you are free to take my findings with a grain of salt. If a unit I reviewed is given or loaned to me in the future, I will say so here.
Company Info and Trivia
Fosi Audio name comes up in the audiophile community every now and then. They have some budget-oriented DACs and amplifiers. According to their website, Fosi Audio was founded in 2017. K5 Pro is the first device I’ve ever tried than came out of Fosi Audio. But I must say, if I had came across this thing at the beginning of my journey, I might have ended my search for good and would not have become an audio enthusiast at all.
Let me tell you a funny story. I like gaming as much as the other guy and although they are not my first choice, I play some competitive shooters too. Whenever I played with my brother, he complained how my microphone sounded so bad and cut off. Of course, at first, I tried buying better gaming headsets but they didn’t help at all. Then I decided to try a cheap external DAC/ADC because my onboard ADC was probably too noisy so noise cancelling was cutting off while trying to filter the noise out. Although it was better, I wanted a little more improvement, so I bought an audio interface and a condenser microphone. Microphone problem was solved but there were weird pops and clicks in the audio output. Then I tried better DACs but, in the end, I learned that the problem was caused by ethernet drivers.
Long story short, while I was searching for a solution to one problem always another thing came up and along the way I’ve learned a little about audiophilia and noticed I wasn’t enjoying listening to music as much as I did when I was younger. Thus began my chase after musical enjoyment. Anyway, that’s all for that boring story so thank you for putting up with it.
Packaging, Build and IO
Packaging
K5 Pro comes in a simple box. In fact, it is pretty similar to Topping and S.M.S.L. when it comes to packaging. In the box you get a USB-C to USB-C/A cable, a microphone and headphone splitter cable, an optical cable and a user manual.
Build
Fosi Audio K5 Pro Gaming DAC/Amp is made out of aluminum. Although it doesn’t feel premium, I can say it is pretty well built.
IO
On the front, there are two 3.5 mm inputs for headphone and microphone. Above the inputs there are three led lights those indicate the input chosen. To the right, there are Bass, Treble and Volume control knobs in that order from left to right. Volume knob is a multifunction one that turns the device on and off by pressing long and changes the input with short presses. Volume knob is a little wiggly but bass and treble knobs feel solid. There is no button or switch to kill or reset the tone controls but they click to neutral position when turned to 12 o’clock so I assume it kills the tone controls somehow.
On the back there are three inputs. USB input also doubles as power. If you are using the device with through USB, you don’t need external power but if you want to use coaxial or optical as input you need to connect K5 Pro to an external power source. In my test it drew 5.2V and 0.2A. My Android phone and Tablet could power K5 Pro. However, the iPad I borrowed from Mahir had problems. Every time I tried, at first it powered the DAC and played music but then cut off the audio. I also tried a power delivery hub but it didn’t help either.
My Nintendo Switch also worked with K5 Pro when it was connected to its dock but couldn’t power the device in handheld mode, not that I would use it that way. Official statement says K5 Pro also works with PS5 if connected through USB-C, however if you want to use it with other devices such as XBox you need to use the optical input.
Apart from digital inputs, there are left and right RCA outputs so you can use K5 Pro with your active speakers or another power amplifier. Unfortunately, I didn’t try that configuration.
Sound of K5 Pro Gaming DAC/Amp
Output
Power
Fosi Audio K5 Pro has decent driving power for most of the headphones. The hardest to drive headphones I have are 600 Ohm DT880. They reached decently satisfying volume when I maxed out the knob. My HD600 was at a pretty good level above 12 o’clock. So I can confidently say they have enough power if you don’t have some notoriously hard to drive headphones.
Noise
In terms of noise floor, I can’t say K5 pro is dead silent. One of the most sensitive IEMs I have is Audiosense AQ4 and they hissed with K5 Pro while my S.M.S.L. SP400 was dead silent. But my other IEMs fared a little better; there were very little or no hiss.
Tonality
Describing K5 Pro’s sound is not very complicated because tuning is not very nuanced like other DACs and Amps. First thing I noticed when I started listening to it was it was noticeably rolled off on both subbass and upper treble. So I can confidently say K5 Pro is not a linear DAC/Amp. Funnily enough it sounded very clean which surprised me a lot because on the other hand the sound was not very technical or resolving. So, after playing with tone controls, I wanted to try measuring it. Tone controls were well implemented and didn’t cause any noticeable distortion by the way.
As you can see in the measurements there is a slight dip in the midbass area. I think this tuning is genius for competitive gaming as it would reduce any boomyness that would come out of any regular gaming headset or commercial headphone and help you hear positional cues more easily. Therefore, my impression of clean sound came into light here. I noticed my Audiosense AQ4 sounded like Moondrop Variations in neutral position. Bass knob is exclusively increases subbass and even if you max it out what you get is around 12 dBs of subbass and only 4 dBs at 200 Hz.
Upper Mids and Treble is also rolled off in neutral position. So, I would advise to increase treble a little for competitive gaming if you are having problems. However, that might not be necessary as this roll off is only around 2 dBs.
Technicalities
Unfortunately, K5 Pro couldn’t satisfy my audiophile needs. It isn’t very resolving and technical. I can say it has a decent amp and fun tone controls but DAC is mediocre. I noticed it smeared notes a little. Also, I could hear faint pops and clicks occasionally. While listening to busier passages, K5 Pro lost its composure and stumbled a little. It probably sounds a little worse than a good dongle in this sense.
EQ and Spatial Audio
K5 Pro doesn’t come with an app. Similar devices have dedicated apps that would have EQ settings and spatial audio. For me this is not a deal breaker, since Windows have their own Sonic. I even bought Dolby Atmos for a decent price some time ago. Most of those are gimmicks anyway. Also, I like analog tone control knobs more than EQ and even if I want to fine tune something, I could always use Equalizer APO.
Input
Microphone input or the ADC is the part that I was the most interested in about K5 Pro. From the samples I recorded, I can say it has a decent ADC. It sounded clean and crisp. Recording was loud and noise floor could be heard when microphone volume was maxed out. But when I reduced it in Windows settings, noise disappeared and recording was much cleaner. I compared it with the output of my audio interface and surprisingly at similar gain levels, noise levels were also similar. I think that is very unfortunate because if there had been a microphone volume knob, I wouldn’t mind the noise floor I heard as I wouldn’t max out the volume anyway. Just know that microphone has more gain than your average PC microphone input so you don’t need to max it out in settings.
Conclusion
Fosi Audio K5 Pro has been a device I enjoyed tinkering with a lot. I can see myself using it in my gaming sessions already, if I can find time that is. Although it falls a little short in terms of audio quality compared to other audiophile products, as a gaming DAC/Amp it is more than proficient. I prefer it to most of the other similarly priced Gaming DAC/Amp solutions for sure. Of course it has much room for improvement but, I know most of those would raise its price. Still, I’d loved to see a microphone volume knob. We are still far from a DAC/Amp that would rule them all but Fosi Audio came a little closer.