Fosi Audio DS3 – ES9039Q2M USB-C DAC/AMP Dongle, 7.1 Spatial Audio and FPS Gaming Mode
109,90 € Inc. VAT
109,90 € Inc. VAT
Fosi Audio K7 – AK4493S Desktop DAC/AMP, 2100mW Balanced, Bluetooth aptX HD
The Fosi Audio K7 is a desktop DAC and headphone amplifier built for the overlap between gaming and serious listening. It runs AKM’s AK4493SEQ VELVET SOUND DAC, Texas Instruments’ TPA6120A2 amplifier and Qualcomm’s QCC3031 Bluetooth chip – components found in dedicated audiophile hardware – in a compact aluminum chassis that fits under a monitor and works directly with PS5, Switch and PC without drivers or configuration.
Chipset architecture
The AK4493SEQ is AKM’s current flagship stereo DAC, capable of PCM decoding up to 384kHz/32bit and DSD256 via USB, with 123dB dynamic range and 0.00007% THD+N at chip level. Upstream, the XMOS XU208 handles USB audio processing – it has been the reliable standard for desktop USB audio for years, guaranteeing stable hi-res transmission and a clean USB-to-audio handoff.
The amplifier section uses a dual-mono TPA6120A2 configuration, combined with OPA1612 op-amps for the signal. The result is 600mW @32Ω single-ended and 2,100mW @32Ω balanced – enough to drive Hifiman planars, Sennheiser HD 800 and everything in between without hitting the limit. The noise floor measures ≤2.5μV single-ended and ≤6.5μV balanced: no audible hiss in IEMs, no background noise in sensitive headphones.
Balanced Output – What It Means
The K7 runs completely balanced circuits from the DAC to the headphone output – it’s not a split-from-single-ended design. The 4.4mm output delivers ≤0.0002% THD with a dual-mono amp stage. For headphones with detachable cables, using a 4.4mm terminated cable gives you the full balanced signal, lower crosstalk and power headroom the amp was designed for.
Inputs & Connectivity
Front panel: 3.5mm microphone input (adjustable gain, requires UAC 1.0 mode), 3.5mm single-ended output, 4.4mm balanced output. Rear panel: USB-C (PCM 384kHz/DSD256), Optical (PCM 384kHz/DSD256), Coaxial (PCM 384kHz/DSD256), Bluetooth 5.0 antenna, RCA outputs. The included 3.5mm splitter converts a 4-pin gaming headset into separate headphone and microphone connections – without an additional adapter for existing gaming setups.
PS5 Pro and PS5 work via USB-C in UAC 1.0 mode (plug-and-play). UAC 2.0 requires the Windows driver and disables the microphone input. The XMOS firmware can be updated via USB-C.
Controls & Display
Two large knobs: left for volume (with long-press gain toggle), right for bass/treble/menu navigation. Five shortcut buttons for input selection, bypass and display control. The 1.5″ monochrome LCD shows input source, sample rate and current settings in real time. Bypass mode levels the signal in less than two seconds.
Team’s Take
The K7 sits in a category dominated by Creative and FiiO for years – the desktop DAC/AMP for players who also listen to serious music. What Fosi got right is the chipset: the AK4493S is genuinely warm and musical without being colorful, and the TPA6120 has enough current delivery to make the 2,100mW balanced a spec with real meaning and not just marketing. At this price, you’re not compromising on the chip to pay for the chassis – the aluminum build is legitimately premium.
The honest caveat: the microphone input requires UAC 1.0, which limits USB audio to lower sample rates. For voice chat in gaming this is irrelevant, but if you’re monitoring your microphone for streaming or recording while playing hi-res audio, you’ll find the limitation. For most setups – IEMs or headphones on a PC or PS5 – this is the most complete desktop unit we have in the catalog.
⚠️ Note Microphone + PS5: Microphone input and PS5 compatibility require UAC 1.0 mode. UAC 2.0 (required for 384kHz/DSD256 on PC) disables the microphone input. Switch modes in the display menu after switching on.
IN THE BOX
- 1× Fosi Audio K7 DAC/AMP
- 1× DC 12V 2A power supply
- 1× USB-A/C to USB-C cable
- 1× Bluetooth antenna
- 1× 3.5mm Headphone and Microphone Splitter
- 1× User Manual
| SPECIFICATION | DETAILS |
|---|---|
| Model | Fosi Audio K7 |
| Type | Desktop DAC/Headphone Amplifier |
| DAC Chip | AKM AK4493SEQ (VELVET SOUND) |
| USB Processor | XMOS XU208 |
| Headphone Amp | Texas Instruments TPA6120A2 (dual-mono) |
| Op-Amp | OPA1612 |
| Bluetooth Chip | Qualcomm QCC3031 |
| Max Decoding (USB) | PCM 384kHz / 32bit – DSD256 |
| Max Decoding (Optical/Coax) | PCM 384kHz / 32bit – DSD64/128/256 |
| Bluetooth | 5.0 – aptX HD – aptX LL – aptX – SBC – AAC – PCM 24bit/48kHz – Range ≤13m |
| Output Power (3.5mm SE) | 600mW @32Ω |
| Output Power (4.4mm BAL) | 2,100mW @32Ω |
| THD (SE / RCA) | ≤0.0005% |
| THD (Balanced) | ≤0.0002% |
| SNR | 122dB (3.5mm SE) – 121dB (4.4mm BAL) |
| Noise Floor | ≤2.5μV (SE) – ≤6.5μV (balanced) |
| Dynamic Range | 121dB |
| Frequency Response | 20Hz – 20kHz (±0.1dB) |
| Inputs | USB-C – Optical – Coaxial – Bluetooth 5.0 – 3.5mm Mic |
| Outputs | 3.5mm SE – 4.4mm Balanced – RCA |
| UAC Mode | UAC 1.0 (PS5/mic) – UAC 2.0 (PC hi-res) |
| Gaming Compatibility | PS5 Pro – PS5 – Nintendo Switch – PC – Mac – Linux |
| Gain | High / Low (switchable via knob) |
| EQ Controls | Bass – Treble – Bypass mode |
| Display | 1.5″ LCD monochrome |
| Controls | 2 large multi-function knobs – 5 shortcut buttons |
| Protection | Overheat – Overload – Overcurrent |
| Chassis | CNC aluminum alloy – Anodized – Angled ergonomic design |
| Power Input | DC 12V 2A (included) |
| Firmware | XMOS upgradeable via USB-C |
| Product Weight | ~530g |
| Dimensions | ~150 × 90 × 30mm |
| Available Colors | Black – White |
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