Delivery time approx. 2 weeks

Questyle SIGMA – Portable DAC & Headphone Amplifier

The name “SIGMA” derives from the 18th letter of the Greek alphabet Σ from the mathematical symbol for sum. In this sense, the portable DAC/Amp SIGMA embodies the sum of all audio innovations from Questyle.

SIGMA was born from the uncompromising pursuit of excellence. It features an innovative TTA decoding architecture and supports decoding rates of up to PCM 768 kHz and DSD512 – a performance otherwise only achieved by desktop devices. The patented CMA technology (Current Mode Amplifier) ensures professional performance in a compact format in combination with a fully discrete and fully symmetrical design.

Main features at a glance

• Outstanding audio performance: Equipped with the highly dedicated AK4493 DAC chip from AKM and Questyle’s own TTA architecture for desktop-level sound.

• Patented amplifier technology: Four sets of fully discrete, fully symmetrical CMA headphone amplifiers (Global PCT Patent No. US 9,614,483 B2).

• MFi certified by Apple: Official certification guarantees flawless compatibility and optimized power management with iPhones, iPads, and the entire Apple ecosystem.

• Premium Bluetooth (v5.4): Certified for Qualcomm Snapdragon Sound™ and Sony LDAC. Supports aptX Adaptive (CD-quality lossless as well as high-resolution up to 24-bit / 96 kHz).

• Special mode for in-ear monitors (IEMs): Dedicated IEM signal processing minimizes the signal path and offers ultra-fine 64-step volume control for an absolutely noise-free listening experience.

• No battery worries: Built-in 4300 mAh lithium battery for up to 12 hours playback. The dual USB-C system cleanly separates data transfer and charging.

Technical data

Device Overview & Connections

Audio Outputs

• 3.5 mm Jack (Single-Ended): For standard headphones and IEMs.

• 4.4 mm Jack (Balanced): Fully balanced output for maximum dynamics.

• Note: Outputs can be switched by a switch from headphone operation to Line-Out can be switched to connect the device to active studio monitors or hi-fi systems.

Intelligent Dual USB-C System

• USB DAC IN (Audio Port): Transmits audio data only. The device does not draw power from the smartphone, preserving phone battery.

• CHARGE IN (Power Port): Separate port exclusively for charging the internal battery (supports charging during use).

Controls & Switches

• Power Button: Hold for 2 seconds to power on/off ; short press for battery display.

• Function Button: Short press to switch input source ; long press for Bluetooth pairing mode.

• Volume Buttons (+ / -): Single click for 1 step ; long press for continuous adjustment.

• IEM/HP Switch: Switches between Optimized IEM Mode and Standard Headphone Mode.

• Gain Switch & HOLD Switch: For Adjusting Gain and Locking Buttons.

LED Status Indicators

• Audio Source: Separate LEDs for Bluetooth, USB, Gain Level, Data Stream, and Active IEM Mode.

• Battery & Volume Indicator: LED Matrix for Capacity Levels (25%, 50%, 75%, 100%).

Package Contents & Accessories

• Questyle SIGMA Portable DAC/Amp Unit

• USB-C to USB-C Cable (12 cm)

• USB-C to USB-C Cable (120 cm)

• USB-A to USB-C Adapter

• Warranty Card & User Manual