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Re: Decode tapes using Dolby Noise Reduction

Posted: Sun Sep 26, 2010 10:40 am
by waxcylinder
The other outside chance would be to scour around for a stand-alone Doby-B encder/decoder box.

I remember the first ever "domestic" Dolby unit that I ever encountered was just such a box which an audiophile friend of mine went out and bought (at vast expense at the time) to enhance the recordings with his top-end R2R deck. Of course pretty soon after that the Dolby processing was included in most good tape and cassette decks.

There are probably still some of those stand-alone devices gathering dust in attics/garages around the world - you never know, you might strike it lucky ...

WC

Re: Decode tapes using Dolby Noise Reduction

Posted: Mon Sep 27, 2010 12:53 am
by Gale Andrews
kozikowski wrote:<<<Don't know what you mean by "circumstances">>>

Circumstances. Like: "I was Director of Engineering for IBM Content Management around 2002 and one of the participants in the "Skunkworks" outside of Poughkeepsie NY, wrote a Dolby B decoder module on the back of a Piggly-Wiggly napkin and brought it to work.

Richness of detail like we're always trying to get our posters to give us.
Richness of detail in questions too. I thought you meant "technical circumstances under which the plug-in would do what it claimed to do". As I said, I don't at the moment have any details to hand and even if I did, I know the original URL is dead. But it looked impressive with some technical background of the author given, graphs of before and after etc.

The main thing for me, given there is no known plug-in that really does simulate Dolby de-emphasis, was to suggest something the OP could do (without buying anything) that would have some sort of desired effect. It's agreed here and in other answers to this question that an EQ on its own won't replicate Dolby playback of Dolby material.



Gale

Re: Decode tapes using Dolby Noise Reduction

Posted: Tue Sep 28, 2010 9:58 pm
by gmushlin
Since I own a cassette recorder with Dolby B & C that has better specs than most reel to reel decks, I was wondering if I could record the tape without the Dolby B setting and then play it back using the Dolby B setting on the cassette recorder? Then I'd run that to Audacity and use a tape hiss filter. I know it isn't as good as having a reel to reel with Dolby, but it would be a lot cheaper. Maybe it would be good enough.

Re: Decode tapes using Dolby Noise Reduction

Posted: Tue Sep 28, 2010 11:37 pm
by billw58
gmushlin wrote:I was wondering if I could record the tape without the Dolby B setting and then play it back using the Dolby B setting on the cassette recorder? Then I'd run that to Audacity and use a tape hiss filter. I know it isn't as good as having a reel to reel with Dolby, but it would be a lot cheaper. Maybe it would be good enough.
Brilliant! No reason that I can see why it shouldn't work. Well, one ...

Level matching will be critical. If the R2R tapes have a Dolby tone at the start, then you're good. Play back the tape and set the cassette deck record level so the Dolby tone records at the "double-D" mark on the meters. If you have no tone then it's by guess and by gosh.

-- Bill

Re: Decode tapes using Dolby Noise Reduction

Posted: Wed Sep 29, 2010 5:05 am
by gmushlin
Thanks for your reply.

My next step is to acquire a Reel to Reel deck. If the price is right, I'll go with a dolby deck. If not, I'll take a stab at the Cassette deck method, which will probably be by guess and by gosh, as I don't ever remember hearing a Dolby tone on those tapes when making them.