Fosi Audio DS3 – ES9039Q2M USB-C DAC/AMP Dongle, 7.1 Spatial Audio and FPS Gaming Mode

Fosi Audio DS3 – ES9039Q2M USB-C DAC/AMP Dongle, 7.1 Spatial Audio and FPS Gaming Mode

The Fosi Audio DS3 is the first battery-free DAC/AMP dongle to integrate XMOS POWERED processing – a dual-core 1.6GHz engine combined with the ESS ES9039Q2M, delivering 122dB of SNR and THD+N below 0.0003% in a 16g body. It works in two different modes: HiFi for critical listening and Gaming for spatial audio on PS5, Switch and PC – with no driver installation required for either.

Chipset architecture

The ES9039Q2M is ESS’s compact flagship DAC, supporting PCM up to 32bit/768kHz and native DSD512. The dual-core XMOS POWERED processor handles USB audio decoding with stable, jitter-free lossless streaming – it’s not a standard USB controller. The combination delivers 120mW @32Ω on the single-ended 3.5mm output and 220mW @32Ω on the balanced 4.4mm output, with a noise floor low enough for sensitive IEMs.

Gaming Mode – Spatial Audio by Hardware

In UAC 1.0 mode, the DS3 activates 7.1 spatial audio processing at hardware level. Fosi’s integrated algorithm reconstructs 7.1-channel game audio into a 360° soundstage without any software. A dedicated FPS mode further amplifies directional cues – footsteps, reload sounds, gunshots – for positional accuracy in competitive titles. Switch between no effect, FPS and 7.1 with a combination of buttons on the device itself. Compatible with PS5, Nintendo Switch and PC, plug-and-play.

HiFi and PEQ mode

UAC 2.0 mode activates the full 32bit/768kHz decoding path for critical listening. Eight selectable digital filters allow you to fine-tune the reconstruction filter to your preference. The 8-band PEQ is adjustable via a browser-based web panel with hardware-level processing – EQ changes are applied to the signal path without software intermediaries or latency. Volume settings are stored independently between UAC 1.0 and UAC 2.0 modes.

Construction and Design

CNC aerospace aluminum chassis with tempered glass window that makes the internal circuits visible. Two hardware volume buttons on the side, LED indicator on the rear. Fosi’s signature orange bezel around the glass face. At 16g and 55 × 20 × 11mm, it disappears into a pocket or sits flush against a cell phone. Available in Galaxy (silver) and Obsidian (black) to match the Fosi IM4 IEMs.

Team opinion

The DS3 is where a dongle stops being a dongle and becomes a real portable DAC. The XMOS POWERED processor is a genuine differentiator – it’s not just a better USB controller, it’s what allows the ES9039Q2M to operate at its real ceiling instead of being limited by the interface. Hardware spatial audio is the feature that makes this relevant for gamers who don’t want a desktop setup: plug-and-play PS5 with 7.1, no drivers, no software, just plug it in and use the button combination to activate FPS mode.

At this price, the competition is real – the FiiO KA15 has more raw power, others have screens. But none combine the XMOS POWERED architecture, hardware gaming modes, balanced output and PEQ in something so light. For IEM users who play games and listen to music, it’s the most complete dongle in our catalog. It’s not for demanding high-impedance planars – for that use case, the K7 is the right answer.

⚠️ iOS Note: Requires USB-C to Lightning or USB-C to USB-C adapter for use with iPhones. Not included.

⚠️ Note Gaming mode: 7.1 Spatial Audio and FPS mode only work in UAC 1.0. Full decoding at 768kHz requires UAC 2.0 (HiFi mode).

IN THE BOX

• 1× Fosi Audio DS3 DAC/AMP Dongle
• 1× USB-C to USB-C cable
• 1× USB-C to USB-A adapter
• 1× Quick Start Guide
• 1× User Manual