Fosi Audio K7

| 2100mW | Bluetooth | DSD256 | 16-300Ω |

The Fosi Audio K7 is born as a DAC & headphone amp able to cover the needs of both audiophiles and gamers/streamers.

Fosi Audio has plenty of audio amplifiers, digital-to-analog converters, preamps and other audio components but so far their products were orientated to audio-enthusiasts and audiophiles.

Instead, the Fosi Audio K7 joins their catalog with features and design elements that can attract the attention of gamers as well.

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Fosi Audio K7 Review

Tests & Scores

Accessories & Packaging

The Fosi Audio K7 is packed inside a fairly large box with sufficient soft foam protection.

With the unit you will also get:

BT antenna
Y-audio splitter
USB cable
PSU

^3.75_/5

Design

The Fosi Audio K7 has a cute, compact size and design that makes it a small space-occupying audio device to be used in, even, desktops with reduced dimensions.

The chassis is built with smooth rounded edges and a slightly canted form, improving the accessibility and reach of the controls and screen.

As you can see from the photos, the device has 2 very large knobs on the top chassis and an orange-colored scale on the base of them, these scales could seem to be backlit but are not, they are static and painted-printed on the surface beneath a transparent cover.

The design alignment, with all control elements placed on the top area of the device might not fit every user’s system; mostly if you have arranged a desk, audio, PC environment thought around a more classic style with front-facing controls and display.

The unit has a stylish and attractive design and them with the combination of black with orange accents; that also matches the design and colors of the display’s user interface.

On the front panel you will find all the headphone and mic connectors while the rear panel is the place where you will find the remaining I/O connectors, Bluetooth antenna and power connection.

^4.75_/5

Operation & Control

Thanks to plenty of physical buttons and 2 multi-function knobs, the Fosi Audio K7 is much more friendly and fun to use and operate.

In total, the device has 5 pill-shaped buttons with small but clear printings sitting below them to identify each button’s function. The 2 knobs present an orange dot accent that can serve to give a visual guide of the level that you have set in each knob, yet the knobs rotate infinitely clock and anti-clockwise.

These knobs provide a silent but tactile per-notch feedback enabling better fine-control and step by step dialing up/down of volume/bass/treble and also menu navigation.

Of course, the main operation and control aid is the 1.5″ LCD screen that gives information of the current settings and real-time displaying of the corresponding knob controlled level.

When pressing the knobs you will hear a click sound and tactile feedback, though we could say that the feedback sound is not the best on the market as you can hear some hollow and metallic noises.

^4.5_/5

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Display Screen

A screen with just 1.5″ might seem tiny on paper but it matches the device dimension quite well and uses a smart UI that is able to show with clarity all the needed audio-related info as well as the connectivity and settings details.

Moreover, despite being aiming upwards, the screen is fully visible at any angle without any loss of visibility nor awkward negativization effects.

A minor detail to point out is that the volume range starts at “0” but does not reach “100”, instead the maximum level of the UI uses a scale from 0 to 62. Another odd fact is that the volume steps go by 3 points (instead of 1) from 0 to 24, then steps are by 2 points from 26 to 32, after which jumps to 33 (1 point step), 36 (3 step), 38 to 52 by 2 steps and finally after 52 by 1 step until the max. (62)

Despite this, both Bass and Treble controls are based on a dB scale that can be controlled by 1dB per step and going from -12dB to +12dB for bass and -6dB to +6dB for treble; leaving out any guesswork or strange scale equivalency.

^4.25_/5

Construction & Build

The build overall is phenomenal as we have seen on most other modern audio devices from Fosi Audio that we have reviewed so far.

Metal has been the material of choice to construct the entire case, chassis and details of the unit – even the bottom plate if made of the same hefty metal quality.

Therefore, despite being a small DAC/amp, the K7 is much heavier than other similarly sized audio components – and this is a positive thing as this Fosi Audio device feel remarkably premium for such a low MSRP.

Worth mentioning, though, that despite being also made of metal, the 2 large knobs, unfortunately, wobble a bit.

^5_/5

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Connectivity

We were surprised to find the amount and variety of input and output connections available in the Fosi Audio K7, with 3 output connections and 4 inputs, this is not a quantity of I/O that you usually can get at this price point.

Specifically, the Fosi Audio K7 gives you the following I/O ports:

Output

3.5mm single-ended headphone
4.4mm balanced headphone
RCA

Input

USB-C
Optical
Coaxial
Bluetooth 5.0
3.5mm microphone

I/O sound specs

USB:PCM 384kHz-32bit/DSD256
Optical: PCM 24bit/192kHz
Coaxial: PCM 24bit/192kHz
Bluetooth: PCM 24bit/48kHz
Bluetooth codecs: SBC, AAC, aptX, aptX HD, aptX LL

With a core design around gamers/streamers, the Fosi Audio K7 offers a wide range of coverage for PC, console, mobile and handheld gaming devices that can benefit from superior headphone and microphone quality while adapting to the connectivity of you device whether it is wired or wireless.

^4.5_/5

Sound

Maybe unexpectedly to some, the Fosi Audio K7 might have a cheap price and tiny size but it is an astounding performer.

On top of that, inside, the unit carries audiophile-grade components such as XMOS XU208 chip, AKM AK4493SEQ 32-bit DAC chip, multi Texas Instruments OPA1612 op-amps, NJW1119A 3-band tone control IC, NJU72315 2-channel audio volume control IC, Texas Instruments TPA6120A2 headphone amp IC and Qualcomm QCC3031 Bluetooth module.

From a less nerdy-techy point of view, you will love to know that this small DAC/amp is able to boast an impressive 2100mW of output to drive your headphones. In fact, when we tested several all-time classics such as a Sennheiser HD600, Sennheiser HD650, beyerdynamic DT-990/DT-770 (in their 250ohm versions) and even Fosi Audio’s own Fosi Audio i5, the K7 had zero problem to drive all of them with plenty of headroom to push the headphones into deafening levels.

It is important to mention that if you need all the power from the K7 you need to use the 4.4mm balanced headphone out connection and set the DAC/amp to “High Gain” mode. When using the 3.5mm single-ended connection, the Fosi Audio K7 still reaches a very respectable 660mW of output.

Obnoxious noises like popping on headphone’s connection and scratching potentiometer control were completely absent when testing the K7.

In addition to this, the unit did not exhibit any channel imbalance and absolutely no hiss, while also responded with a faithful sound profile and signature that did altered the original tracks.

When adjusting the Bass and Treble feature, we noticed that the dB boosting were accurate with what the brand declares in real-time through the display screen.

Testing microphones with the K7 was as flawless as using it as a DAC and headphone amp, allowing clear, noise-free gaming and streaming sessions thanks to the internal intelligent, automated noise-reduction system.

A dedicated “bypass” function is incorporated in the Fosi Audio K7 allowing to bypass all the custom audio settings that you might have applied, we found the feature to be a nice addon but the unit takes around 2 seconds to switch into and back from the bypass mode.

Sound Technical Specifications
Headphone Impedance: 120Ω-300Ω
Rated Power Output: 1200mW/32Ω 4.4mm balanced
SNR ≥121dB (balanced), 122dB (single-ended)
Dynamic Range 94dB
THD RCA OUT:≤0.0005%
THD Headphone balanced:≤0.0002%
Noise Floor balanced:≤ 6.5μV
THD Headphone single-ended:≤0.0005%
Noise Floor single-ended:≤ 2.5μV
Frequency Response 20Hz-20kHz (±1dB)

^5_/5

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