DDi Codec: Dolby noise reduction as software


Now that the old cassette is in revival again, there is a practical problem: cassette decks – and certainly with Dolby noise reduction – are sparsely sown. In the heyday of the cassette, Dolby – in various variants of which B and C were the best known – was a widely used method that counteracted tape noise. Many pre-recorded music cassettes were recorded with Dolby B, and if you were in the fortunate possession of a slightly more elaborate deck with Dolby, you recorded yourself with the noise reduction enabled.

An sich system recorded cassettes are also compatible with non-Dolby decks. But if you want to listen to or digitize a cassette ever recorded with Dolby in its original state, a decoder is necessary. And that’s where it goes wrong, because new tape decks with Dolby are not or hardly released. Cheap consumer solutions in the form of simple tapdecks or walkman-like devices don’t have this feature.


The best solution is to score a Dolby-capable second hand cassette deck on eBay or similar. Or go for an ‘NOS’ or New Old Stock copy. Until a few years ago you scored such a deck for a few tens, now unfortunately very expensive. Disadvantage of the second-hand road is that things may have become disturbed by wear and tear; also the decoder may have ‘gone out of its settings’.

To avoid all this misery, a decent Dolby decoder has now finally appeared in software. DDi Codec takes care of this job as a stand-alone program on your Mac or Windows PC. Easily digitize your cassettes to a .wav file, for example using the free Audacity. Did you succeed? Then open that file in DDi Codec and Dolby B or Dolby C will be applied. This can be fine-tuned via settings. For an amount of about €18 a full decoder and you will own this nice encoder. A good deal! If only to digitize those special recordings that have been lying around in the house for decades.

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