Abbey Road (Black Triangle) CD

Fan created remixes and rare variations
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ianbuckers
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Re: Abbey Road (Black Triangle) CD

Post by ianbuckers »

Engonoceras wrote: Wed Jun 16, 2021 12:37 am
michael_charles wrote: Tue Jun 15, 2021 6:08 pm So I have a question. Why does the pre-emphasis version have a higher DR value than the de-emph version?
CDs with pre-emphasis basically have greatly exaggerated treble. The purpose of this was they would cut the treble on playback supposedly reducing added CD Player decoding noise or something at the same time. The process was quickly abandoned because it just wasn't necessary after better D/A decoding came along.
Exactly. Here's the technical explanation...

"In the early stages of CD development, it was planned to make CD a 14 bit format and, even at the launch in 1982, most of the commercial digital to analogue converters were only 14 bit devices.

With only 14 bits resolution, quantisation errors on critical programme were perceptible and so the Red Book CD standard allowed for the inclusion of optional, analogue pre-emphasis of the signal prior to analogue to digital conversion with corresponding analogue, treble de-emphasis filter after conversion back to analogue in the player.

This technique raised the level of the treble modulation prior to the A to D converter to a point where the quantisation noise was a smaller proportion of the signal level, thereby improving linearity. And the de-emphasis in the player further reduced the audibility of the remaining quantisation errors by attenuating the high frequencies where they are most easy heard.

The presence of emphasis was signalled by a dedicated control bit in the recorded bitstream which the CD player detected and switched in the de-emphasis filter as required.

By the end of the 1980s, converters had improved enormously and were delivering a performance which rendered emphasis and de-emphasis obsolete and its use gradually fell out of fashion and favour."

Got that now? No? Okay I admit it...I don't understand all of that either! lol. But basically it was to do with players initially using 14bit ADCs.
Engonoceras wrote: Wed Jun 16, 2021 12:37 am A real shootout would be taking the Toshiba "Abbey Road" with emphasis intact, extracting one track (I suggest "Something") and then applying multiple "de-emphasis" plugins to produce multiple de-emph'd versions and see (a) what the differences actually are (b) what people prefer. I would do it but I don't have the time and don't want to track down plug-ins.

There is the SoX plugin
http://sox.sourceforge.net/

There is "IIR filter" that will work with Foobar. You select the filter with the option "CD De-Emphasis" selection.

There's also an Audacity plugin. In the old days may have been a VST plugin.

I did my de-emph conversion years ago but I forgot what plugin I used it may have been one of those or something different.
The pre-emph curve is really simple...

Image

Really simple for a computer programme to reverse engineer accurately and so there's not really any latitude for differences in the decoding by different plug-in's.

P.S: Your link for sox is just the homepage for the sox project...not a link to a de-emph plug-in.
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paul62
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Re: Abbey Road (Black Triangle) CD

Post by paul62 »

Many of the people who've contributed to this thread (including Engonoceras) are members at The Row: it's a shame that we didn't have this thread over there...ah, well!!!
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ianbuckers
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Re: Abbey Road (Black Triangle) CD

Post by ianbuckers »

paul62 wrote: Wed Jun 16, 2021 9:13 am Many of the people who've contributed to this thread (including Engonoceras) are members at The Row: it's a shame that we didn't have this thread over there...ah, well!!!
You put it here Paul.

It's kind of become 2 different discussions on one thread. You are EQ matching to an LP. Engonoceras, myself and others are off on the pre-emphasis thing and reversing it.

I've uploaded a couple of files for you, Engon or anyone interested to compare...

https://www.filefactory.com/folder/cb012581c21124c8

...comments on any differences and/or which sounds better please.
hogshead of hellfire
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Re: Abbey Road (Black Triangle) CD

Post by hogshead of hellfire »

It would now be less expensive (though, still three figure$) to acquire the same master source used for that cd (and: having 14-years'-LESS AGE on it at the time, as a further bonus): the Toshiba/Apple, 7 1/2ips reel of catalog no. PXA-5031.

The issues of worrying about authentic provenance and digital transfer are all eliminated in such a case.
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paul62
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Re: Abbey Road (Black Triangle) CD

Post by paul62 »

But a seven and a half inch per second dub of the master reel dupe that Toshiba has, which was made to be sold to hi-fi enthusiasts back in the day, should be great as long as it was well-cared for. If one of those can be sourced and then transferred and digitised with care, using a well-made and well-maintained top quality reel-to-reel deck et cetera, then it should be something worth listening to. (It might be easier and cheaper to find a genuine Black Triangle CD (and a vintage Toshiba CD player from 1983 to match) to hear that master tape dupe Toshiba has (in the best possible quality available to ordinary consumers)).
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924Gilman
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Re: Abbey Road (Black Triangle) CD

Post by 924Gilman »

Hi Paul.

I was listening to the normal Black Triangle and was shocked to notice how Pro-Use was so much louder (which I like) I was investigating how to make Black Triangle EQ’d similarly and stumbled upon this. Is it possible to re up the fixed Black Triangle you worked so hard on ? I’m a big fan btw! Thanks for all your work!
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paul62
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Re: Abbey Road (Black Triangle) CD

Post by paul62 »

924Gilman wrote: Thu Oct 21, 2021 8:43 pm Hi Paul.

I was listening to the normal Black Triangle and was shocked to notice how Pro-Use was so much louder (which I like) I was investigating how to make Black Triangle EQ’d similarly and stumbled upon this. Is it possible to re up the fixed Black Triangle you worked so hard on ? I’m a big fan btw! Thanks for all your work!
Sure! Glad you like these things I've shared!!

Abbey Road (Black Triangle CD EQ-matched to Pro Use LP 'drop)

hxxps://gofile.io/d/2usm3p
"Dedicated Downloader Of Beatlegs"...!!! (Raymond Douglas Davies, Paul Sixtytwo)

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924Gilman
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Re: Abbey Road (Black Triangle) CD

Post by 924Gilman »

Hi Paul!

When I click on it I’m prompted with “ this address is invalid”
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paul62
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Re: Abbey Road (Black Triangle) CD

Post by paul62 »

You have to copy the address, open a new tab on your browser, paste the address into the new tab and then edit the address to make "hxxps" into "https"!
"Dedicated Downloader Of Beatlegs"...!!! (Raymond Douglas Davies, Paul Sixtytwo)

And when he does
His little rounds
'Round the forums
We have around
Eagerly pursuing
All the latest vids and discs
'Cause he's a dedicated downloader of Beatlegs!
924Gilman
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Re: Abbey Road (Black Triangle) CD

Post by 924Gilman »

An absolute masterpiece

THANK YOU !
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