Fosi Audio Hearing Amplifier K7

A new player for a wide audience
For a relatively newly established brand, Fosi Audio has a wide reach in the hi-fi market. From signal sources, through headphone and speaker amplifiers, to loudspeakers and home cinema solutions. Now, their fleet is expanding with the K7 headphone amplifier and DAC, aimed especially at gaming and multimedia.

Its main advantage is its wide compatibility and usability. In addition to a set of traditional digital inputs and a Bluetooth module with aptX HD codec, there is also a 3.5mm microphone input with noise reduction. The K7 supports connection to the PS5, PS5 Pro and Nintento Switch, among others. Outputs here are both RCA for the power amplifier, as well as balanced and single ended for headphones.

-For gaming, music listening and work
-Digital inputs optical, coaxial and USB-C
-Bluetooth with aptX HD and 50ms latency
-3.5mm microphone jack with noise reduction
-RCA output and both 3.5mm and 4.4mm headphone jack
-Wide compatibility with game consoles


Components worthy of true hi-fi
Despite its primary focus, the K7 is no slouch when it comes to reproducing high-resolution recordings either. Its electronic circuitry is fully symmetrical. A Qualcomm QCC3031 chipset is used to decode the digital signal, along with an Asahi Kasei Microdevices AKM4493SEQ. The power section consists of Texas Instruments OPA1612 and TPA6120 amplifiers.

Maximum decodable formats are 32bit/384kHz and DSD256 in the case of USB input. The symmetrical headphone output offers 2x 2100 mW at 32? for even the most demanding headphones with a high signal-to-noise ratio of 121dB and a harmonic distortion of 0.0002%.

-Fully symmetrical circuit
-Qualcomm QCC3031 and AKM4493SEQ chipset
-Texas instruments OPA1612 and TPA6120 amplifiers
-32bit/384kHz, DSD256 (USB)
-High power 2x 2100 mW at 32?


Practical interface
The entire body, including the controls, is made of aluminum using CNC machining and fine sandblasting. The construction is therefore durable and long-lasting. The top side offers a wide range of controls in the form of two digital potentiometers for controlling volume, EQ, microphone, etc., input, output and power selection buttons, and an LCD display with information on input, playback format and EQ. The design of the unit is user-friendly with ergonomics in mind.

-Sandblasted aluminum body and matte finish controls
Multi-function digital potentiometers and buttons for quick interaction with the instrument
-LCD display with playback information
-Comfortable, ergonomic design


Specifications
4.4mm Balanced Headphone Output
Power: L+R?2100mW+2100mW (32?/THD+N<1%)
SNR: 121dB
THD+N: <0.0002%
Dynamic Range: 121dB
Noise Threshold: ? 6.5µV

3.5mm Single-Ended Headphone Output
Power: L+ R?600mW+600mW (32?/THD+N<1%)
SNR: 122dB
THD+N: 0.0005%
Dynamic Range: 121dB
Noise Threshold: ?2.5µV
Range: 20Hz-20kHz (±0.1dB)

RCA Output
Output Level: ?2Vrms
Range: 20Hz-20kHz (±0.1dB)
THD+N: 0.0005%
Dynamic Range: 121dB
Noise Threshold: ?3µV

AKM4493SEQ DAC
USB Sampling:PCM 384kHz-32bit/DSD256
Output level 2.1W per channel (symmetrical)
Body Material Aluminum
Display 1.5 inch color
Colour black
Accessories included Power adapter, USB-C cable (USB-A reduction), Jack 3.5 audio cable (splitter)
Warranty period 24 months according to the Consumer Protection Act, 24 months also for purchases made with an I.C.O.
D/A chip manufacturer Asahi Kasei Microdevices
Bluetooth version 5.0
Condition New
Bluetooth codecs AAC, SBC, aptX™, aptX™ HD, aptX™ LL
Outputs Jack 3.5 mm, Jack 4.4 mm, RCA Cinch
Inputs Bluetooth, Coaxial, Optical, Microphone, USB Type C