MQA Decoding Explained
If you play back a 24-bit/192kHz MQA-encoded file using iTunes through a regular DAC (i.e. a non-MQA DAC), you will get a 24/48 file.
If you play back a 24-bit/192kHz MQA-encoded file through an MQA software decoder like Tidal HiFi, Audirvana, or (soon) Roon, and you are using a regular DAC (i.e. a non-MQA DAC), you will get a 24/96 file. A software decoder does not offer the ability to 'unfold' the original file to resolutions higher than 24/96 (or 24/88.2).
If you play back a 24-bit/192kHz MQA-encoded file through an MQA-enabled DAC, you will get a 24-bit/192kHz file. If you are also using a software decoder like Tidal HiFi, Audirvana, or (soon) Roon, you can have the software decoder perform the first 'unfold'.
This scenario plays out the same for other resolutions above 24/96 and 24/88.2.
One thing to note: if the original MQA file is 24/48, 24/96, or 24/88.2, it will pass through the software decoder and be 'unfolded' to its original resolution. This brings up the interesting fact that people who love their DAC and its proprietary digital filter may very well be able to have their cake and eat it too, especially when streaming MQA content from Tidal HiFi.
Comments From Bob Stuart
- The strength of MQA is that one file can be played back in a wide variety of situations by the customer.
- The three presentations you discussed: No decode; MQA Core; Full decode are all previewed in the studio. Each is optimally set up for that presentation (with appropriate de-ringing).
- MQA Core (which comes out of the soft decoder or digital outputs) carries the additional information necessary for an MQA Renderer (eg Dragonfly) or a full Decoder (eg MSB, Brinkman, Mytek, Meridian) to 'finish the job downstream'.
- Full software decode is not possible because the DAC must be known and characterized. MQA is an analog to analog process.
- I hate to say it, but I told you so.
For (much) more on MQA, see MQA: Questions and Answers on Stereophile