body {font-family: Arial, sans-serif; background:#f9fafc; color:#222; margin:20px;} .container {max-width:940px; margin:auto; background:#fff; border-radius:12px; box-shadow:0 6px 18px rgba(0,0,0,.08); padding:28px;} h2 {font-size:22px; margin:18px 0 10px; color:#0b4a82;} h3 {font-size:18px; margin:16px 0 8px; color:#0b4a82;} p {line-height:1.75; margin:8px 0;} ul {margin:10px 0 16px 20px;} li {margin:6px 0;} .badges span {display:inline-block; background:#eef6ff; border:1px solid #d4e6ff; color:#0b4a82; padding:6px 11px; border-radius:999px; margin:5px 6px 0 0; font-size:13px;} .specs {width:100%; border-collapse:collapse; margin-top:12px;} .specs th, .specs td {border:1px solid #e6e6e6; padding:10px 12px; text-align:left; vertical-align:top;} .specs th {background:#fafafa; width:280px;} .note {font-size:13px; color:#666; margin-top:10px;} .callout {background:#fff7e6; border:1px solid #ffe1a8; padding:10px 12px; border-radius:8px; font-size:13px; color:#7a4a00;} Questyle SIGMA Pro — Flagship Portable Bluetooth DAC/Amp Studio-grade performance. Portable form. No compromises. SIGMA Pro is Questyle’s newest flagship “all-in-one” portable DAC/headphone amplifier, engineered to bring reference monitoring performance into a truly mobile form factor. It combines dual-mono ESS ES9069Q DACs, Questyle’s patented Current Mode Amplifier with fully discrete, fully balanced output stages, and an XMOS XU316 USB interface for master-grade decoding up to PCM 768 kHz/32-bit, DSD512 (Native/DoP), and MQA full decoding. Dual ES9069Q (Dual-Mono) Current Mode Amp ×4 (Discrete, Balanced) XMOS XU316 USB PCM 768/32 • DSD512 MQA Full Decode Bluetooth 5.4 • Snapdragon Sound aptX Adaptive/HD • LDAC 3.5/4.4/6.35 HP Out 3.5 SE In • 4.4 BAL In Stereo Recording 48 kHz/24-bit Dual USB-C (Charge+Data) 4300 mAh • 12 h Key Features Patented Current Mode Amplifier + TTA: Four groups of fully discrete, fully balanced current-mode output stages under Questyle’s Three-Tier Architecture (TTA) deliver massive headroom, ultra-low distortion and speed. Dual-Mono DAC Architecture: Two ESS ES9069Q chips in dual-mono configuration for superior channel separation, dynamics and resolution. Serious Drive Capability: Peak figures up to 25 Vp-p output swing, >8 W peak power and 5 A instantaneous current (design headroom for difficult loads). Three Headphone Outputs: 3.5 mm SE, 4.4 mm balanced and 6.35 mm full-size for instant compatibility from IEMs to full-size headphones. Dual Analog Line Inputs: 3.5 mm SE (nominal 1 Vrms) and 4.4 mm balanced (nominal 2 Vrms) to integrate turntables/phono stages, mixers or other analog sources. Stereo Line-In Recording: Record analog inputs as 48 kHz/24-bit digital audio over USB with simultaneous monitoring (UAC-class driverless on most OS). Two USB-C Ports: One audio/data-only, one charge-only for play-while-charging and lower phone battery drain. Bluetooth 5.4 with Snapdragon Sound: Supports aptX Adaptive, aptX HD, LDAC, SBC/LE Audio for high-quality wireless input. Long Battery Life: 4300 mAh pack delivers up to 12 hours; smart battery management keeps long sessions stable. Bauhaus-inspired Chassis: Sand-blasted aviation aluminum with Kunlun glass window — minimalist, durable, and striking on any desk. Creator-Ready Connectivity Optical (Toslink) and Coaxial inputs cover legacy digital transports; USB handles modern lossless playback from phones and computers. With 3.5 mm SE and 4.4 mm balanced analog inputs, SIGMA Pro drops into studio and Hi-Fi chains seamlessly. Switch gain manually to match IEMs, studio headphones or desktop monitors via line-out. Wireless, Certified Built on Qualcomm Snapdragon Sound, SIGMA Pro passes both Snapdragon Sound and Sony LDAC certification for robust high-quality wireless audio. It pairs broadly across ecosystems and supports modern Bluetooth codecs for both fidelity and stability. Specifications Model Questyle SIGMA Pro DAC Dual ESS ES9069Q (dual-mono) USB Interface XMOS XU316 • UAC 2.0 Digital Inputs USB (PCM 44.1–768 kHz/32-bit; DSD Native 64/128/256/512; DoP DSD64/128/256; MQA render & full decode)Optical (PCM 44.1–192 kHz/24-bit) • Coaxial (PCM 44.1–192 kHz/24-bit) Analog Inputs 3.5 mm SE In (nominal 1 Vrms) • 4.4 mm BAL In (nominal 2 Vrms) Headphone Outputs 6.35 mm • 3.5 mm • 4.4 mm balanced Output Power (HP) 1200 mW @ 32 Ω (BAL) • 160 mW @ 300 Ω (BAL) • 40 mW @ 300 Ω (SE) Performance THD+N 0.0002% @ 48 kHz/24-bit, 1 kHz sine • SNR 120 dB • FR 20 Hz–20 kHz (+0.8 dB) Gain Control Line & HP Out: L / H / S (Studio) • IEM Out: L / H Bluetooth v5.4 • Snapdragon Sound • aptX Adaptive / aptX HD / LDAC / SBC / LE Audio Recording Stereo recording from analog inputs at 48 kHz/24-bit with live monitoring (USB Audio Class) USB-C Ports 1× Audio/Data (device-powered), 1× Charge (5 V / 2 A), supports play-while-charging Battery / Runtime 4300 mAh • up to 12 h • ~3 h charge time Dimensions / Weight Approx. 155.7 × 85 mm • ~330.8 g System Support Windows XP–11 (UAC2), macOS, Linux, Android, HarmonyOS, iOS/iPadOS (MFi licensed) Package Contents SIGMA Pro Portable Bluetooth DAC/Amp USB-A to USB-C Adapter USB-C to USB-C Cable Warranty Card & User Manual Notes: For maximum drive and stability with demanding headphones, use the 4.4 mm balanced output and appropriate gain. Use the audio/data USB-C for playback and the charge USB-C for power; play-while-charging is supported. Recording function captures analog inputs at 48 kHz/24-bit via USB and requires a compatible app or DAW.
