The Questyle SIGMA Pro is a portable DAC and headphone amplifier that pairs dual ES9069 DAC chips and an XMOS XU316 USB controller with four current-mode amplification circuits. It's meant for listeners driving planars or high-impedance dynamic headphones away from a desk, where a standard dongle runs out of steam.
Who the Questyle SIGMA Pro is for
Planar and high-impedance headphones: It's built for the headphones where a standard dongle runs out of steam.
Serious listening away from a desk: You get desktop-class amplification without a desktop's footprint or power brick.
Upgrading from a dongle DAC: Four amplification circuits in a portable make it a genuine step up rather than a sideways move.
Fans of Questyle's current-mode design: Current-mode amplification is Questyle's signature approach, and this is it in a form you can carry.
Questyle SIGMA Pro key specs
DAC chip: Dual ES9069
USB controller: XMOS XU316
Amplification: Four current-mode amplification circuits
Colors: Silver, Black
Genuine Questyle stock — 45-day returns.
Questyle SIGMA Pro vs similar options
vs FiiO Q7: The Q7 pairs an ES9038PRO DAC with THX AAA 788+ amplification and doubles as a desktop unit; choose the SIGMA Pro for dual ES9069 chips and Questyle's four current-mode amplification circuits.
vs xDuoo XD05 Pro: Built around an ES9039SPRO DAC rather than dual ES9069 chips; pick the SIGMA Pro if Questyle's four current-mode amplification circuits are the reason you're shopping.
Yes. Every unit we sell is genuine and brand-new, shipped in its original packaging, and backed by our 1-year TonePier warranty and 45-day returns.
Where does my order ship from, and how long does it take?
Every order ships from our warehouse in China, with full tracking, and most orders ship within 3 business days. Shipping is free on every order; most US orders arrive within 7–15 business days and most orders to other countries within 7–20 business days — see our shipping policy for details.
What if it isn't for me?
You get 45 days to decide. Keep the packaging, keep it in like-new condition, and send it back for a refund. Ear tips unsealed for hygiene reasons are fine — we expect you to actually listen.
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