There’s no shortage of desktop and portable DAC/headphone amps these days, making it harder than ever to know which ones truly stand out. Questyle, however, has spent nearly a decade leading the charge in digital audio players, desktop headphone amplifiers, and high-performance dongle DACs.
With the introduction of the new Sigma Pro and Sigma Flagship portable DAC/headphone amplifiers, Questyle brings its current mode amplification technology full circle—combining the company’s signature precision engineering with modern features like Bluetooth LE and LDAC support for today’s demanding listeners.
Previewed at CanJam London 2025, the new Questyle Sigma and Sigma Pro portable DAC/headphone amplifiers are set to launch in late October 2025 (Sigma) and early November 2025 (Sigma Pro).
Both models feature a precision-crafted chassis made from CNC-machined aluminum, topped with transparent glass and an RF signal suppression coating—a design that reflects Questyle’s obsession with build quality and signal purity.
Questyle Sigma Pro
The Sigma Pro is engineered to deliver the power, performance, and flexibility of a desktop DAC/headphone amplifier—packed into a far more convenient and portable design.
Key features of the Sigma Pro include the following:
- Flagship DAC: Dual ESS ES9069 DAC chips in a dual-mono configuration deliver exceptional clarity and channel separation.
- Amplification: Features Questyle’s Current Mode Amplifier technology, offering enough power to drive everything from sensitive IEMs to 300Ω headphones.
- Connection Versatility: Equipped with 3.5mm, 4.4mm, and 6.35mm outputs, plus both analog and digital inputsfor maximum flexibility.
- Recording Ready: Converts digital input signals to analog for playback or recording, compatible with home audio setups, studio monitors, and headphones.
- Hi-Res Wireless Audio: Certified for Qualcomm Snapdragon Sound and Sony LDAC for high-resolution wireless streaming.
- Portability: Up to 12 hours of battery life with dual USB-C ports that allow simultaneous charging and playback.
Questyle Sigma
At $599, the Questyle Sigma portable DAC/amp is a step down from the Sigma Pro, although it shares many of its flagship sibling’s features, including Current Mode Amplification, balanced and unbalanced analog outputs, Qualcomm Snapdragon Sound, LDAC support, 768kHz/32-bit PCM playback, and DSD compatibility up to DSD512. It differs in using a single AKM AK4493 DAC chip and omits digital/coaxial/analog inputs, recording functionality, and multi-device monitoring, offering a high-quality experience at a more accessible price point.
Comparison
| Questyle | Sigma Pro | Sigma |
| Product Type | DAC & Headphone amplifier | DAC & Headphone amplifier |
| Price | $899 | $599 |
| USB Input | PCM: 44.1kHz-768kHz/32-Bit DSD Native: DSD64,DSD128,DSD256,DSD512, DSD DoP: DSD64,DSD128,DSD256 MQA: MQA Rendering and Full MQA Decoding Support UAC 2.0 WinXP/Vista/Win7/Win8/Win10/Win11/ Linux/Android/HarmonyOS/macOS and iOS | PCM: 44.1kHz-768kHz/32-bit DSD Native: DSD64,DSD128,DSD256,DSD512, DSD DoP: DSD64,DSD128,DSD256 Support UAC 2.0 WinXP/Vista/Win7/Win8/Win10/Win11/ Linux/Android/HarmonyOS/macOS and iOS |
| Optical Input | PCM 44.1kHz~192kHz/24-Bit | No |
| Coaxial Input | PCM 44.1kHz~192kHz/24-Bit | No |
| Bluetooth Input | Bluetooth 5.4 Support SBC/LE Audio/aptX/aptX HD/LDAC decoding | Bluetooth 5.4 Support SBC/LE Audio/aptX/aptX HD/LDAC decoding |
| Analog Input | 3.5mm SE IN: Standard level 1Vrms 4.4mm BAL IN: Standard level 2Vrms | No |
| Outputs | 6.35mm/3.5mm unbalanced output 4.4mm balanced output | 3.5mm unbalanced output 4.4mm balanced output |
| Recording Function | Analog input recording and simultaneous monitoring 48kHz/24bit fixed sampling | No |
| Gain Control | Three gain settings for Line and Headphone outputs: L (Low), H (High), and S (Studio) Two gain settings for IEM output: L (Low) and H (High) | Manual Gain Option |
| Output Power | 40mW @300Ω SE 160mW @300Ω BAL 1200mW @32Ω BAL Peak Power Output>5W | 1200mW@320 Balanced Peak Power Output>5W |
| THD+N | 0.0002% @48kHz 24bit 1kHz sine | <0.0003% @20mW, 300Ω |
| SNR | 120dB | 120dB |
| Frequency Response | (±0.8dB) 20Hz~20kHz | (±0.1dB) 20Hz-20kHz |
| Battery Capacity | 4300mAh 3.7V | 4300mAh 3.7V |
| Battery Life | Up to 12 hours | >12h |
| Charging | Approximately 3 hours to full charge. Supports 5V/2A charging Dedicated USB-C charging port with support for simultaneous charging and listening | Approximately 3.5 hours to full charge. Supports 5V/2A charging Dedicated USB-C charging port with support for simultaneous charging and listening |
| USB Chip | XMOS XU316 | No separate USB Chip |
| DAC Chip | Dual ESS9069Q | AKM AK4493 |
| Amplifier Circuit | Four sets of fully discrete current-mode amplifier designs | Four sets of fully discrete current-mode amplifier designs |
| Volume Control | 360-degree rotary encoder with Mute button | Traditional +/- level buttons |
| Apple MFi Certification | Yes | Yes |
| The Sigma Pro Package | SIGMA Pro Portable DAC with Headphone Amplifier Type-A to Type-C adapter Type-C to Type-C cable (120cm) Warranty Card & User Manual | SIGMA Portable DAC with Headphone Amplifier Type-A to Type-C adapter Type-C to Type-C cable Type-C Charging Cable Warranty Card & User Manual |
The Bottom Line
Questyle’s Sigma Pro and Sigma portable DAC/headphone amplifiers continue the company’s nearly decade-long legacy of reliability, precise sound quality, and wide format support. Both models feature Current Mode Amplification, high-resolution wireless streaming with LDAC and Snapdragon Sound, and portable designs that make them ideal for on-the-go listening.
The Sigma Pro delivers flagship-level performance with dual DACs, multi-device connectivity, and recording capabilities, while the Sigma offers much of that same core functionality at a lower price point with a single DAC and simplified inputs. With impressive portability, robust build quality, and Questyle’s proven engineering, these could be the portable DAC/headphone amps that serious listeners should prioritize.
Price & Availability
- Sigma Pro – $899 (coming November 2025)
- Sigma – $599 at Amazon (available now)
Related Reading
- Questyle M12i and M15i Dongle DACs Reviewed: Which One Makes the Most Sense For You?
- Questyle M15c Dongle DAC Review: A New Reference Below $150 for A Wide Range of Headphones?
- Questyle’s 2nd Gen M12i and M15i Dongle DACs are Apple MFi Certified
- Questyle M15 Dongle DAC/Headphone Amplifier: Editor’s Choice
