MQA File Playback
MQA files are encoded in a standard PCM container format such as FLAC or WAV. They can be either 16-bit or 24-bit word length, and have a base sample rate of either 44.1kHz or 48kHz, which is dependent on the sampling rate used during the file's authoring process. Because of this, they can be played back on any standard 2-channel file playback device, including any Aurender music server. Further, any standard digital-to-analog convertor capable of handling a PCM file up to 24-bit, 48kHz can play back an MQA encoded file.
Although an MQA file can be played back on any device, the PCM file contains special encoding which MQA have "folded" into the file as a two-stage process which is referred to as "Origami" for audio. To fully experience what MQA has to offer, the best possible treatment of the MQA Origami process involves using hardware based decoding ("unfolding" of the Origami) and tailoring the audio output to a specific digital to analog converter.
A Full Decoder is a hardware solution (digital-to-analog converter) that provides MQA "...stream Authentication, Origami unfold to Core (the first unfold) and then further unfolds with precise file and platform-specific DAC compensation and management according to the hierarchical target. This is the highest possible sound quality."**
- Aurender models A100/A10/A30 contain MQA Full-Decoder DACs, designed and implemented with MQA playback as a priority from the ground up.
- Any DAC-less Aurender server can be connected to a stand alone MQA Full-Decoder DAC to experience MQA playback at the highest level. No further software upgrades on the Aurender side are required to achieve full MQA performance when using an MQA Full-Decoder DAC.
Recently, MQA introduced "Core" decoding: "The first unfold of the Origami recovers all the direct music-related information and makes it available for either analogue or digital output at 88.2 or 96 kHz. Sound quality is higher than from ‘No’ or ‘Authenticating’ decoders but lower than a ‘Full’ decoder. Products containing an MQA decoder may provide a digital output of either the undecoded stream or the Core output – providing they are passed with bit accuracy. The MQA Core signal is also preconditioned for generic DACs."**
- With in-app purchase, all Aurender music servers now implement MQA Core decoding (with the exception of A100/A10/A30, which are already equipped with MQA Full Decoder DAC hardware).
An MQA Renderer is a DAC that"...can take a bit-accurate signal from a Core decoder (containing buried information on how to proceed) and complete the final unfold in its analog context. An MQA Renderer will indicate ‘stream lock’ but is not able to decode an MQA stream or Authenticate it. This type of device is available for portable applications (such as active headphones or portable amplifiers) and for silicon integration. MQA Renderers provide analog output only through their managed D/A conversion."**
*The MQA logo is a trade mark of MQA Limited. © MQA Limited 2017
** All of the information quoted is available at the following link: http://bobtalks.co.uk/blog/science-mqa/mqa-playback/
MQA Content and Aurender Conductor
Local or Tidal MQA Content - A100/A10/A30 Music Server
When using Aurender Conductor with the A100/A10/A30 Music Servers, the decoding and file status of a locally stored MQA file is displayed on the app next to the album. The description will indicate that “MQA" or "MQA Studio” content is being played back.* A green or blue dot next to the MQA logo indicate that the unit is decoding and playing an MQA file, and denotes provenance to ensure that the sound is identical to that of the source material. The blue dot indicates the unit is playing an MQA Studio file, which has either been approved in the studio by the artist/producer or has been verified by the copyright owner.*
* Please note, this feature is specific to the A100/A10/A30 and will not be displayed on any of the other Aurender models.