SMSL PO100 XU316 USB to Optical/Coaxial Adapter - Compact MQA DAC

In this review the SMSL PO100 is assessed as a small, purpose-built USB to optical/coaxial adapter aimed at users who need clean digital output from phones, PCs or streamers. The single biggest reason to buy is its compact MQA decoding and XMOS XU316-based asynchronous USB handling, which provides a stable digital feed to downstream DACs or AV gear without driver fuss on modern Macs and Windows 10 or later. It is a handy travel companion for those who want reliable signal transfer and reduced USB noise in a minimal package.

Key Features

• XMOS XU316 chip: Provides asynchronous USB transmission for stable clocking and reduced jitter when sending digital audio to a backend DAC or streamer.
• MQA decoding: Supports MQA playback without extra software, making it straightforward to output higher-resolution MQA streams to an MQA-capable backend device.
• Dual outputs: Offers both Toslink optical and coaxial outputs simultaneously so the user can feed two devices or choose the preferred digital connection.
• Plug-and-play: Works without drivers on macOS and Windows 10+ for fast setup with modern computers and compatible phones using the included cables.
• Miniature and portable: Extremely small and lightweight for easy transport in a bag or pocket when traveling with a laptop or streamer.
• Accessory kit: Includes USB Type-C to C and USB A to Type-C cables to connect a wide range of phones, PCs and players right out of the box.

Who It's For

The PO100 is best for listeners who already use an external DAC, receiver or streamer and need a clean, portable USB-to-digital interface that supports MQA and standard PCM rates up to 192kHz. It suits mobile users and desktop setups where a compact adapter and simple setup are priorities.

It is not for people who need a standalone DAC with volume control or who want to connect directly to active speakers without a backend device. Audiophiles seeking advanced onboard features like IIS output or integrated amplification should look elsewhere.

Pros & Cons

Pros

• Compact form factor makes it genuinely easy to carry and deploy in portable setups.
• MQA decoding and XU316 asynchronous USB deliver reliable digital output and good signal transfer characteristics.
• Inclusive cables and plug-and-play support on macOS and Windows 10+ reduce setup friction for most users.
• Reported to reduce USB noise and act as a ground-loop isolator in some systems, improving perceived cleanliness of the signal.

Cons

• Does not include volume control and cannot connect directly to active speakers, so a backend DAC or amplifier is required.
• Does not support IIS output like the PO100pro, limiting some niche professional use cases.

Specifications

Chip	XMOS XU316
USB input	Type-C (USB to Type-C and USB A to Type-C cables included)
Outputs	Coaxial and Toslink optical (both available simultaneously)
Sample rates	PCM up to 192kHz, DOP64 supported
MQA	MQA decoding supported without additional software
OS support	macOS and Windows 10 or above (driver-free)
Weight	Approximately 0.75 g (very compact)

Our Verdict

The SMSL PO100 is a practical, low-cost digital adapter for anyone who needs a portable USB-to-coaxial/optical interface with MQA decoding and stable XMOS USB performance. It delivers solid signal transfer and noise reduction benefits for desktop and mobile users, but it requires a backend DAC or amplifier since it has no volume control and cannot drive active speakers directly. For what it does, it represents sensible value.

Frequently Asked Questions

Does the PO100 require drivers?
It is driver-free on macOS and Windows 10 or later, so most users can plug and play.

Can it play MQA files?
Yes, the PO100 supports MQA decoding without additional software, but you should set your computer volume to max for best output when playing MQA.

Can it connect directly to active speakers?
No, the PO100 cannot be connected directly to active speakers; it must feed a backend DAC, receiver or amplifier first.