Correcting Dolby A recordings on CD releases

edited December 2019 in Other music
A certain gentleman by the name of John Dyson has made it his mission to correct the bright, scratchy and otherwise awful sounding early CD releases.

He has discovered that many original masters were recorded using Dolby A but not decoded when layed down for CD release. To add insult to injury many of these were also subject to "Wall of Sound" or "radio friendly" adjustments without decoding from Dolby A at any point.

He has been creating a complex programme/algorithm ( still ongoing ) aimed at correcting these incorrect CD releases to bring the music back to or at least much closer to, what the musicians and producers originally intended.

The story has been unfolding on a couple of forums with before and after samples/tracks available for download and constructive criticism.

To save rehashing all the blurb here I will give the links to the forum I follow for this ( I hope that's OK Dave, if not simply delete this ) and let John explain for himself, along with reactions to his efforts. Some of the older links within to samples may now be dead but the more recent ones are still there.

The beginning and explanation

Some ongoing information and music

Most recent and more developed

Check it out for yourselves and see what you think.


  • Just an extra point to make, the older the sample links are the less down the route of development so less effective than the newer ones where John has made many improvements along the way.
    It is still an on going project.
  • Thanks for this CJ.
    Fascinating all round.
    I've had a quick scan through the threads, and downloaded the available files, although John seems to have removed some of them. I see he sites understandable "storage issues" in his Dropbox.
    Haven't had the chance to listen yet. But will do so.
  • Have you indulged yet Ben?
    Dave as well.

    You guys have better speaker systems than me, it would be interesting to read your experience with this.
  • Not yet!
    Haven’t even written my Christmas cards.
    I will do both ASAP.
  • edited December 2019
    I've started to listen to John Dyson's generous offerings.
    Thanks again for putting us on to these CJ. Mr. Dyson has got a good thing going on!

    As the ABBA 'Me and Bobby...' MP3s were the only ones I could find with multiple versions available, I've listened mainly to those.
    I find it a ghastly song, and badly recorded. So not a lot of fun.*
    But interesting.

    Clearly there's a difference in sound between the non-Dyson digital ones, and the Dyson digital ones. (And also between the various individual Dyson ones.) The Dyson ones sound softer whilst preserving detail; much more like the vinyl copies he includes with the set. Definitely more listenable over the longer periods. The non-Dyson digitals sound like they have a significant lift somewhere in the higher frequencies that boosts the attack on guitar strings, percussion and sibilants. Presumably that is one of the unwanted legacies of the Dolby A processes. Initially this upper-lift sounds more detailed, but quite quickly (10 seconds) becomes tiresome. A bit like a one-note subwoofer effect, but in the treble region.

    John has also made available some FLACs that he has processed. 'A Taste of Honey', 'Casino Royal' and 'Spanish Flea'. These sounded very good indeed. Delicate but dynamic. Detailed but warm. Better than the Abba MP3s that Mr. Dyson had passed through his magic machine. How much that is to do with the original recordings and how much to do with their being FLAC files I don't know. One of them had really loud and raspy trumpets on it, that could easily have tipped over into piercing hash. They did not.

    John is clearly a clever bloke. That's good work he's doing there.

    I've also downloaded the Carpenters MP3s, but haven't listened to these properly yet.
    John seems to like Phil Collins. So there's a couple of his albums as FLACs there too. I'm not sure I have the determination for those.  

    * Edit: My wife said she used to like it till half an hour ago. After hearing the first 90 seconds played 20 times she's not so sure.
  • Sorry. I've been inundated with family stuff and haven't yet stuck my ear in.

    Sounds fascinating, though.
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