ORFS (Original Sampling Frequency) For MQA files

Recently I did a simple experiment to find out how this ORFS information is derived from. I downloaded 2L test bench MQA file and playback on Roon. You will see something like this…

See the bottom of the album, I circled in red, this is ORFS. Now open a tag editor such as Kid3, modify the file with the following tag circled in red.

The value 352800 in whole number corresponds to 352.8k, now change this value to 44100 which corresponds to 44.1k. Save it and let Roon detect again. See below:

Bingo! now Roon reports as 44.1k! It seems this type of detection is based on the tag called ‘ORIGINALSAMPLERATE’, modify the value and Roon will report based on this. This is simple experiment everyone can do.

If those who have MQA DAC, I suspect changing this value will cause the DAC to report whatever value you put inside.

What does the signal path look like for the “44k” version?


MQA authentication can determine the actual ORFS without relying on tag. Whether Roon makes use of it (or tag), I don’t know.

Nope it shows 352.8k and Authentication ’ MQA studio 352.8k’ when the file is being played.


So it is a bug?

It isn’t a bug as such is it? It only becomes an issue if someone goes in and changes that tag (or it is incorrect to begin with). I suppose it is necessary to identify MQA rates to non MQA systems.

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When browsing albums, Roon displays the information based on Meta data.

When playing the album, Roon is processing the file (potentially authenticating and decoding) and therefore has precise information to display in the signal path.