Disclaimer
Hello everyone! I want to be as clear as possible and start by letting you know that the K7 was provided to me by Fosi Audio in order to make this review. I’m not getting paid for this review, and Fosi hasn’t told me what to write, when to publish it, or even asked to see the review before I share it with you.
Everything I’m sharing here is based entirely on my personal experience with the K7. While I try to be as fair as possible, this is still my opinion, and we all have our own preferences, so your experience might be different.
Big thanks to Fosi for giving me the chance to try out the K7, and of course, a huge thank you to you, the readers, for your time and trust. I really appreciate your support!
Introduction
The K7 is a device I’ve been looking forward to for quite some time. As Fosi announced it a long time ago, and when I got it, I was very excited and wanted to quickly see how it performs. Fosi markets this as their gaming DAC+AMP, but don’t let that label fool you, as it’s not just for gamers. The K7 brings an excellent audio quality that’s perfect for audiophiles too.
It’s packed with high-tier components and features that make it stand out. It has a powerful headphone amp capable of 2.1W from its 4.4 balanced output, and the K7 is designed to handle everything that you throw at it, from gaming sessions to music listening with ease and with a very clean sound. So whether you are into competitive gaming or just want great sound for your favorite tracks, this device truly promises a lot.
So, let’s dive in and see how it performs in real world use!
Unboxing
When I received the Fosi K7, it felt just like the unboxing experience with their other products, like the SK02, for example. It is minimal and straightforward. Although the packaging is simple, it is well-organized, giving me the impression that everything was designed to keep the device safe and make it easy to get started, and that’s the most important thing for me.
Inside the box, I found:
- The Fosi K7 itself.
- A USB-C with an attached USB-A adapter to USB-C cable for connecting to your computer or other devices.
- A Bluetooth antenna for wireless audio.
- A 12V power cable to power the device.
- A Y-splitter for connecting headsets with a microphone.
- A user manual with clear instructions to help you set everything up.
Everything is tucked away in compartments, so nothing feels loose or out of place. The whole unboxing process is quick and easy, and all the essentials are included to get the K7 up and running right out of the box. It’s simple, functional, and just works.
Technical Specifications
Internal Chips
- DAC Chip: AKM AK4493SEQ.
- USB Controller: XMOS XU208.
- Bluetooth Chip: Qualcomm QCC30301 with Bluetooth 5.0 support.
- OP Amplifier: OPA1612
- Amplifier Chip: TPA6120.
Features
- Headphone Amplifier: Drives headphones with impedance from 16Ω to 300Ω, with 2.1W per channel for 4.4mm balanced output.
- Digital-to-Analog Conversion: Supports up to PCM 384kHz/32-bit and DSD256 via USB. Optical and coaxial inputs support PCM 24-bit/192kHz.
- Bass (-12dB to +12dB) and Treble (-6dB to +6dB) Controls: Adjustable tone settings to fine-tune the sound, and from my understanding, based on the information that was given to me by Fosi, the changes are wide and gradual. The bass is being changed from 20Hz all the way to 800Hz, gradually. And the treble adjustment is from around 1kHz all the way to 20kHz, and yet again, gradually, so it sounds pretty smooth.
- Bypass Mode: Preserves the original audio signal by bypassing tone controls.
- Versatile Outputs: Includes RCA line-out, 3.5mm single-ended, and 4.4mm balanced headphone outputs.
- Microphone Input (10 levels): Dedicated 3.5mm input for connecting a mic, and the Mic controls are working only in UAC 1.0.
- Multi-Function Knobs: Volume adjustment (62 steps, but they are a bit different; 0-24 are in jumps of 3, 24-52 in jumps of 2, and 52-62 are by single steps), gain control, and tone/mic adjustments.
- LCD Display: Shows volume, gain, input/output mode, sample rate, and adjustments (bass/treble/mic).
- Bluetooth 5.0: Supports SBC, AAC, aptX, aptX HD, and aptX LL for wireless audio (unfortunately no LDAC), and up to PCM 24-bit/48kHz.
Controls and Inputs/Outputs
Front Panel:
- 3.5mm single-ended headphone jack.
- 4.4mm balanced headphone jack.
- 3.5mm microphone input.
Top Panel:
- Volume/Gain Knob: Rotate for volume, short press to toggle gain (low/high).
- Bass/Treble/Mic Knob: Adjust sound settings or mic volume.
5 Buttons:
- Power (short press for UAC mode toggle).
- Input mode selector.
- Output mode selector.
- Bypass toggle.
- Tone/Mic selector.
Back Panel:
- RCA line outputs.
- USB-C input.
- Optical and coaxial digital inputs.
- Bluetooth antenna port.
- 12V DC power input.
Specifications
Headphone Outputs
4.4mm Balanced Output:
- Power Output: L+R ≥ 2.1W+2.1W (32Ω, THD+N < 1%).
- SNR: 121dB (A-Weighted).
- THD+N: <0.0002% (A-Weighted).
- Noise Floor: ≤6.5µV (A-Weighted).
- Frequency Response: 20Hz–20kHz (±0.2dB).
3.5mm Single-Ended Output:
- Power Output: L+R ≥ 600mW+600mW (32Ω, THD+N < 1%).
- SNR: 122dB (A-Weighted).
- THD+N: 0.0005% (A-Weighted).
- Noise Floor: ≤2.5µV (A-Weighted).
- Frequency Response: 20Hz–20kHz (±0.1dB).
RCA Line Output:
- Output Level: ≥2Vrms.
- SNR: 121dB (A-Weighted).
- THD+N: 0.0005% (A-Weighted).
- Noise Floor: ≤3µV (A-Weighted).
- Frequency Response: 20Hz–20kHz (±0.1dB).
Bluetooth:
- Version: 5.0.
- Supported Formats: SBC, AAC, aptX, aptX HD, aptX LL.
- Range: ≤13m (around 39 ft).
Power and Compatibility:
- Input Voltage/Current: DC 12V 2A.
- USB Compatibility: Windows (driver required), Mac OS X, Linux (driver-free).
- Firmware: XMOS firmware upgradeable via USB-C.
Build and Design
The design of the Fosi K7 feels really well thought out. It’s compact and very solid, and it is just the right size to make it feel durable and convenient to use without being too chunky. The build quality is great, with full metal casing that makes it feel premium.
What I really like is that the controls are all on the top. This makes it easier for me to adjust and see what I’m doing, and it looks very good in my opinion. The layout is super clean. There’s a big volume knob on the left, which also works as a gain switch, just press it to toggle between low and high gain. It’s smooth to turn and feels sturdy.
Next to the knob, there’s a 1.5 Inch LCD screen that displays everything clearly, like the volume level, input mode, and even the format or sample rate. It’s bright enough to read easily, and the icons and labels make it intuitive to figure out what’s going on, but I would say that it could have been a bit bigger.
On the top right, there’s another knob for controlling the bass, treble, or microphone volume. It’s nice to have that extra control if you want to tweak the sound, and mainly for gaming, where you may want some extra bass for casual games in order to make the explosions more powerful and dynamic. Or when you are playing competitive games and you need to hear those steps, it can be useful to tweak the treble a bit higher. Below that, there are five buttons for power, input selection, output mode, bypass toggle, and tone/mic settings. They’re responsive and easy to use, though I do wish they were backlit for better visibility in low light.
On the front panel, you get a 3.5mm microphone input, a 3.5mm single-ended headphone jack, and a 4.4mm balanced headphone jack. Having the 4.4mm option is a must have in my opinion because it’s becoming a standard for high quality audio gear.
The back panel is just as impressive. There’s an RCA output, coaxial and optical inputs, a USB-C input, and even a port for the Bluetooth antenna, and of course the power input. It’s nice that everything is clearly labeled and easy to access, whether I’m connecting it to a TV, speakers, or headphones.
Sound Performance
Sound Quality
The K7 sounds super clean and natural across the entire frequency range. It’s neutral, which means it doesn’t add any extra flavor to the music—what you hear is true to the source. Whether I’m listening to music, gaming, or watching a movie, the sound feels smooth and clear. There is absolutely no background noise, crackles, or distortion, even with sensitive headphones. It’s just clean, pure sound, which I really love.
Bass Performance + EQ
The bass on the K7 is punchy and quick. It’s not overwhelming, but it’s strong and deep enough to give music or games that satisfying low end “oomph”. The cool part is you can tweak the bass to your liking using the tone controls. As I have mentioned earlier, the adjustment is happening from 20Hz all the way up to 800Hz, and the changes are gradual, so it never feels like you’re making a big, jarring shift. The lower the frequency, the more volume it adds or decreases, so it won’t muddy up the mids with a big lift. So this lets you dial in just the right amount of warmth and impact without it getting muddy.
Treble Performance + EQ
The treble is very crisp and detailed. And with the tone controls, you can tune the higher frequencies, and here the changes take effect from 1kHz to 20kHz, and just like with the bass, the adjustments are smooth and gradual. The higher the frequency, the more noticeable the volume changes. This makes it easy to add a little sparkle to your music or tone things down if it’s too bright. It’s great for competitive games, where you really need to hear the tiniest things, like enemy steps from far away.
Ease of Use
Using the K7 is super simple. Switching between USB, Bluetooth, or optical inputs is quick and easy, and the controls are straightforward. I love how responsive it is, as when I adjust something, it reacts instantly. The knobs and buttons feel solid and satisfying to use, and everything is clearly labeled, so I never feel lost when I’m tweaking settings, although in a darker environment the lack of backlight to the buttons can make it pretty hard to know what I’m pressing.
Bluetooth Performance
The Bluetooth on the K7 is reliable and easy to use. Pairing is a very easy and quick process, and once it’s connected, the range is solid, and I can walk around my room without losing the signal. Streaming music or game audio over Bluetooth sounds almost as clean as a wired connection, which honestly surprised me. It’s perfect for casual listening or when I just don’t feel like turning my PC on. The only downside for me is the lack of LDAC streaming, which is strange to see as it is pretty much a standard nowadays.
Technicalities
This is where the K7 really shines. It’s detailed and precise, so I can hear every little nuance in my music or games. The soundstage is open and spacious, making everything feel immersive, whether it’s Hans Zimmer’s soundtracks or in game explosions. Imaging is great too, and I can easily tell where each sound is coming from, like footsteps in a game or instruments in a song. For something labeled as a gaming DAC/amp, it definitely performs amazingly for music as well.
Fosi K7 vs. FiiO K11 R2R
I know, I know, they are very different; the price is pretty different, and of course the K11 R2R uses a different technology, and the DAC section is an R2R while the K7 is Delta Sigma. But I felt the need to compare, as the K11 R2R is a very popular option nowadays, and I wanted to show you guys, and it competes with something a bit different but still worth considering.
So let’s break it down:
Sound
The K7 has a punchy, fast bass that feels more controlled. It’s tight and clean. The K11 R2R, though, has deeper, more rumbly bass, which can feel fuller but less tight and detailed.
When it comes to mids and treble, the K7 has a bit more detail and sparkle at the highs, which makes it sound clearer, more detailed, and a bit airier. The K11 R2R sounds warmer and smoother overall, so it’s a bit more laid back. If you like a more neutral, detailed sound, the K7 is the way to go, in my opinion. But if you prefer something warmer and softer and want to try an R2R DAC, the K11 R2R might be the one for you, and it’s a bit cheaper.
Power
The K7 is definitely more powerful. It puts out 2.1W from the balanced output, while the K11 R2R only gives 1.3W. This means the K7 is better if you need to drive harder to power headphones like planars or high impedance ones. The K11 R2R can still power most headphones, but it might struggle with tougher ones.
Design and Size
Both are compact, but the K7 is taller and more rectangular, so it takes up less width, which is great if you don’t have a lot of space. The K11 R2R is more square and sits lower to the table. If height isn’t an issue, the K7 is a bit more compact overall.
Controls
The K7 is easier to use. It has two knobs (one for volume and one for tone adjustments) and five buttons for switching between inputs and other settings. It gives you more control and feels more hands on.
The K11 R2R is simpler with just one knob that does everything, including power, volume, and input selection. It’s minimal, but you might feel limited compared to the K7.
Features
The K7 has Bluetooth, which is a huge plus. You can connect wirelessly to your phone, gaming console, or anything else. The K11 R2R doesn’t have Bluetooth, so you’ll always need a wired connection.
The K7 has a Mic input and also adjustable bass and treble settings. The changes are smooth and gradual, so you can really tune the sound to your liking. But to be honest, I don’t think that it will be useful for audiophiles, as they tend to not change anything with the sound at all or use a PEQ for precise frequency adjustments for each headphone or IEM.
Value
The K7 is $199, and the K11 R2R is $160. The K7 might cost a little more, but in my opinion it gives you a lot more, like better controls, more power, and Bluetooth. The K11 R2R is a good choice if you are on a tighter budget or want a warmer sound, and of course if you want to try an R2R DAC.
Conclusion
The Fosi K7 really surprised me with how good it is. Even though it’s labeled as a gaming DAC/amp, it’s got way more to offer. The sound is super clean and natural, with punchy bass and detailed treble, which, of course, you can tweak to your liking with the build in “Bass” and “Treble” adjustments. Whether I was gaming, listening to music, or just watching a movie, it sounded fantastic every time.
The design is practical and easy to use. I love that it has so many controls right on the device and even Bluetooth for wireless setups. It’s also powerful enough to handle pretty much any headphones, so I never felt like it was struggling. But it still has some cons in my opinion, like the lack of backlit buttons, LDAC support for its Bluetooth connection, and maybe the smaller screen, which would definitely be nicer if it were a bit bigger.
Overall, for $199, it’s hard to find something this versatile that does so much. If you want a DAC/amp that’s great for gaming and, of course, for music, the Fosi K7 is definitely worth checking out.
Pros
- Excellent, clean, natural, and detailed sound.
- Built in Bass and Treble adjustments.
- Powerful output (2.1W balanced).
- Versatile Connectivity with USB, Bluetooth, optical, coaxial, and RCA outputs.
- Intuitive Controls with two knobs and five buttons for easy controls.
- Beautiful and high quality design.
Cons
- No backlit buttons.
- No LDAC support.
- The screen could have been bigger.
