Amazon.com: THX Onyx Portable DAC Headphone Amplifier: High Resolution Audio DAC for Smartphone/PC/Home Audio - THX AAA - MQA Renderer - Direct Stream Digital (DSD) - ES9281PRO DAC - Magnetic Cable Management : Electronics
Archimago's Musings: REVIEW / MEASUREMENTS: Drop + THX AAA 789 Linear Headphone Amplifier. And on Audioholics' THX Onyx DAC/amp "review" with a dash of MQA nonsense...
Portable DAC Headphone Amplifier - THX Onyx™ | Razer United States