Search results for query: mqa

The Dragonfly DACs use one of the ESS chip built-in filters for non-MQA material. Which one depends on the model. Although they deny it, iFi DACs use one of the MQA filters (I don't recall which one) as default. Some other DACs have been observed to use a normal filter until an MQA file is...

I'd like to see Rob Watts and Bob Stuart debate filter design.

Sound a bit too much like MQA.

...are low-pass filters, and as long as they are close enough to an ideal one, the end result will also be good enough, even if they differ. The MQA filters are, of course, anything but good, what with them hardly filtering anything at all. The fact that MQA content can sound good at all only...

That is incorrect. Non-MQA content uses one of the built-in filters of the ESS DAC. For MQA content, they set one of 16 custom filters as requested by said content. I found this out by tapping the I2C bus inside the device.

This document describes it: https://code.videolan.org/mansr/mqa/blob/master/mqa.rst The low 8 bits (sometimes more) can be stripped/altered, and the file will still be recognised by a decoder. This is how MQA-CD is made.

You appear to be confused. What you describe is the excuse for MQA. It's purpose is to enrich Bob Stuart.

The infinite improbability drive is obsolete. Behold the infinite impossibility drive.

Does the new middle tier deliver MQA but block decoding? That's evil.

There's too much confusion around various types of MQA tags, flags, and stripping thereof. I want to see samples.

That is incorrect. Roon runs the file through the MQA decoder, producing a 96 kHz signal. This is then processed and marked for MQA "rendering" which is trivial. That is what goes out to the DAC.

Where does this idea about the bit allocation come from? It is wrong. Starting from the top, the vast majority of MQA files look like this: ~13 bits meaningful PCM data ~2 bits (shaped) dither noise 1 bit MQA metadata + some data 8 bits MQA data, not present in 16-bit files, ignored if...

The "secret" MQA files will be recognised by a DAC that supports decoding. The missing tags are only FLAC metadata that some software uses, mainly for informational purposes.

For non-MQA material, the ES9038Q2M built-in "minimum phase slow roll-off" filter is used.

Negative.

MQA is all about "selective availability." Even the earliest patent filings and other docs talk about enabling varying levels of quality on playback depending on whether the user has purchased a licence, either generic or for a specific file.

The official MQA position appears to be that it shouldn't be tested, and any attempts to do so will not be tolerated. In a way, their reaction tells us more than the actual tests did.

I'm not aware of any MQA-capable CD players. You're expected to send the digital output into an MQA DAC, not that there are many supporting MQA over S/PDIF.

If MQA isn't DRM, why is it touted as "protecting the crown jewels"?

Yes, but the worst I've seen in reality is the MQA stream being one bit above the LSB, so ~12 bits of (mostly) audio data. It's also possible for most of the PCM data to be encrypted, but I haven't seen any such files. They would be unplayable without a decoder.