The SIGMA portable DAC/Amp embodies the culmination of Questyle’s audio innovations. Featuring an innovative TTA decoding architecture and supporting up to PCM768 and
DSD512 decoding capabilities—matching the performance of desktop-class equipment, the patented CMA technology combined with a fully discrete, fully balanced design delivers professional-grade performance in a portable form factor.It specifically incorporates an IEM signal processing circuit and mode settings, ensuring an absolutely ultra-low-noise experience with IEMs.

SIGMA integrates a 4300mAh lithium battery and a dual USB-C port intelligent battery energy management system.It utilizes Qualcomm's high-performance Bluetooth 5.4 chip and is certified for both Qualcomm Snapdragon Sound™ and Sony LDAC, guaranteeing premium wireless audio quality.

SIGMA incorporates four sets of fully discrete, fully balanced CMA headphone/output amplifiers. The patented Current Mode Amplifier achieves both powerful drive capability and refined sonic character within a portable size. The fully discrete CMA delivers peak power up to >5W, peak current up to 3A, enabling exceptional dynamic drive capability.

For decoding performance, SIGMA uses the highly acclaimed AK4493 DAC from AKM and is engineered with Questyle’s TTA architecture to deliver desktop-class audio performance. SIGMA's high resolution grants it an ultra-low noise floor, achieving -130dB in Questyle's lab test environment.

The SIGMA features both 3.5mm single-ended and 4.4mm fully balanced output. Combined with manual gain selection and output mode settings, it drives sensitive IEMs, highimpedance
headphones, and Hi-Fi audio systems perfectly.

The Sigma has a dedicated IEM Mode. In this mode, the signal path is minimized, and ultra-fine 64-step volume control is enabled, ensuring the optimal listening experience with sensitive in-ear monitors.

The SIGMA features two separate USB-C ports, separating power transfer from data transfer.

Using just the data port draws charge out of SIGMA's own 4300mAh battery for up to 12 hours of playback time.

The power port can be used to charge the SIGMA and can be used during operation for prolonged fixed-location use.