Frequently Asked Question
Question: On my Mac it shows the DAC maxing out at DSD128 but I thought the ZEN DAC handles 256?
Answer: The ZEN DAC supports DSD256 only via ASIO.
If using WASAPI (Windows) or Core Audio (Mac) DSD128 is the maximum since DoP (DSD over PCM) must be used.
Mac uses Core Audio drivers only (Apple deleted ASIO support from their OS with the release of OSX), there is no ASIO support on Mac.
Unfortunately macOS does not understand DSD. That’s why the DSD over PCM standard has been defined: to send native DSD data inside what macOS believes to be a PCM stream.
But this has a drawback: as it needs to embed markers for the DAC to recognize it as DSD, the needed bandwidth is doubled. Thus on macOS, only half of the DAC max DSD rate is available.