Questyle Sigma PRO – Flagship Portable DAC & Bluetooth Headphone Amplifier

The Questyle Sigma PRO is a flagship portable DAC and headphone amplifier designed to deliver true desktop-class audio performance in a compact, versatile form factor. Combining dual ESS ES9069Q DAC chips, Questyle’s patented Current Mode Amplifier technology, and advanced wired and wireless connectivity, the Sigma PRO is engineered for audiophiles, studio professionals, and serious music enthusiasts seeking uncompromising sound quality.

Whether used as a high-resolution USB DAC, a powerful headphone amplifier, or a premium Bluetooth receiver, the Sigma PRO provides exceptional clarity, dynamic authority, and ultra-low distortion across a wide range of headphones and audio systems.

Flagship Dual DAC Architecture

At the heart of the Sigma PRO are dual ESS ES9069Q DAC chips configured in a true dual-mono design. This architecture enhances channel separation, reduces crosstalk, and improves overall dynamic range and resolution. Questyle’s TTA three-tier decoding architecture ensures precise digital signal handling before conversion to analogue, delivering natural tonality, refined detail, and expansive sound staging.

The Sigma PRO supports ultra-high-resolution audio playback, including PCM up to 768kHz / 32-bit and native DSD up to DSD512. Full MQA decoding and rendering is also supported for authenticated high-resolution streaming and file playback.

Patented Current Mode Amplifier Technology

Questyle’s fully discrete Current Mode Amplifier (CMA) circuitry is the foundation of the Sigma PRO’s powerful yet controlled sound signature. Unlike traditional voltage-mode designs, current-mode amplification offers superior speed, low distortion, and exceptional transient response.

With four independent amplification circuits, the Sigma PRO is capable of driving demanding full-size headphones while maintaining a silent background for sensitive in-ear monitors. The result is effortless dynamics, precise imaging, and outstanding control across the frequency spectrum.

Comprehensive Connectivity for Portable and Desktop Use

The Sigma PRO is engineered to integrate seamlessly into a wide range of listening setups.

Headphone Outputs
3.5mm single-ended
4.4mm balanced
6.35mm single-ended

Digital Inputs
USB-C (UAC 2.0)
Optical (Toslink)
Coaxial SPDIF

Analogue Inputs
3.5mm
4.4mm balanced

This versatility allows the Sigma PRO to function as a portable DAC/amp, a desktop DAC, or a central audio hub for computers, smartphones, gaming consoles, CD transports, and Hi-Fi systems.

Advanced Bluetooth 5.4 Wireless Performance

The Sigma PRO features Bluetooth 5.4 with support for high-resolution codecs including Qualcomm Snapdragon Sound, Sony LDAC, aptX Adaptive, aptX HD, LE Audio, and SBC. This ensures stable, low-latency wireless transmission with excellent audio fidelity.

Apple MFi certification enables seamless compatibility with iPhones and iPads when used via USB.

Portable Power with Desktop Authority

Despite its high output capability, the Sigma PRO remains portable thanks to a built-in 4300mAh rechargeable battery. Playback time reaches approximately 12 hours, depending on usage and output mode.

Dual USB-C ports allow simultaneous charging and playback, ensuring uninterrupted listening whether at home or on the move.

Technical Specifications

DAC Section
Dual ESS ES9069Q DAC chips (dual-mono configuration)
PCM support up to 768kHz / 32-bit
Native DSD64 / DSD128 / DSD256 / DSD512
Full MQA decoding and rendering

Amplifier Section
Patented fully discrete Current Mode Amplifier
Peak output voltage approximately 25Vp-p
Peak output current approximately 5A
THD+N below 0.0002%
Signal-to-noise ratio approximately 120dB

Output Power
Balanced 4.4mm: approximately 1200mW @ 32Ω
Balanced 4.4mm: approximately 160mW @ 300Ω
Unbalanced 3.5mm: approximately 40mW @ 300Ω

Connectivity
USB-C (UAC 2.0)
Optical (Toslink)
Coaxial SPDIF
3.5mm analogue input
4.4mm analogue input
3.5mm, 4.4mm and 6.35mm headphone outputs

Wireless
Bluetooth 5.4
Qualcomm Snapdragon Sound
LDAC
aptX Adaptive
aptX HD
LE Audio
SBC

Battery
4300mAh internal battery
Up to approximately 12 hours playback
Approximate 3-hour charge time
Simultaneous charging and playback supported

Construction
CNC-machined aluminium chassis
Transparent front panel design
Portable yet robust desktop-ready form factor

Why Choose the Questyle Sigma PRO?

Flagship dual-DAC architecture for exceptional clarity and channel separation
Powerful current-mode amplification capable of driving demanding headphones
Ultra-high-resolution PCM and DSD playback
Advanced Bluetooth 5.4 with premium codec support
Versatile connectivity for portable and desktop systems
Premium aluminium construction with refined industrial design

The Questyle Sigma PRO is a true reference-grade portable DAC and headphone amplifier that bridges the gap between desktop performance and mobile flexibility. For listeners who demand power, precision, and premium build quality in one complete solution, the Sigma PRO delivers uncompromising audio excellence.

Brand	Questyle
Colour	Black, Silver