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The Ayatollah Buggeri

Recovering Tracks From An Unfinalised Audio Cd

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I do quite a lot of transcribing oral history recordings from 1/4" tape and glass/acetate gramophone records. My usual workflow is to take the turntable's output through a specialist (i.e. non-RIAA) preamp and into a standalone CD audio recorder (a Philips CDR-870). From there, I rip the CDs using Adobe Audition on a PC and carry out any further processing needed, e.g. noise reduction or speed adjustment, and render into the format required - usually MP3s for reference and uncompressed 16-bit .WAVs for preservation. The reason for this is that the input signal processing on the standalone recorder is much better than that on my PC's sound card.

I've recently had an intermittent problem with the CDR-870, in that it sometimes won't finalise the discs properly. It'll say that it's done it, and the disc will still play back on the recorder itself, but put it in a PC and it won't read it at all (I've tried with various flavours of Windows, Mac OS and Ubuntu). I've now got a CD that represents a day's work in record-cleaning, multiple passes with various styli, and transferring, and would prefer not to write it off and have to do the whole job again.

I've Googled 'recover unfinalised CD', and have only been able to find either adverts for expensive software (often with blog posts claiming that it didn't work) or procedures for recovering CDs that were part-burned using a computer, not a standalone CD audio recorder. Does anyone have any suggestions? I suspect that the long-term solution is to bite the bullet and get a decent sound card (which I would seriously consider if one was available with a built-in phono preamp that could apply the pre-RIAA 78 EQ curves, but AFAIK none has ever been made), and capture directly. But if anyone can suggest a solution for recovering this CD (for which I am willing to pay a few quid, but not a software package costing £50 plus), it would be gratefully appreciated.

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If the disk plays ok in the source CDR but no where else, wouldn't it be easiest to just take the line outs from the CDR and record to something else?

eg: If you have a mate with another CDR or a PC with a half decent sound card, just link the 2 to make a copy.

Good luck.

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3 things:

(1) what speed are you burning the discs on on the Cd recorder - I find slower speed makes CDs easier to read by various other players

(2) have you changed the CD rom reader in your PC, or even your PC, or is it old/worn/dusty-lens etc? CD drives in PCs vary in their ability to read disks, try a different PC to read it?

(3) what factory-origin of disks are you using - I understand there are only a handful of factories w0orldwide that actually make CD-Rs, RWs etc, basically all the different high street brands are just branded versions of these. Best and most reliable/readable by a long margin are ones from the Taiyo Yuden factory, can get these from ebay, often carrying a major brabnd (TDK etc) on top, but referred in the ebay listing as taiyo-yuden dye.

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Many thanks folks. Spot: yes, this is the final option. However, the CD recorder doesn't have a digital (SPDIF or optical) output, meaning that I'd have to transfer the audio via analogue, thus causing signal degredation in the two lots of conversion. OK, given that the source material was recorded in 1935 and '36, this isn't going to be a big deal, but the purist in me is kind of uneasy about it!

In answer to Si1:

1 - real time (1x): the standalone recorder has no other option.

2 - there are three optical drives in my PC, the newest of which is less than six months old. I've tried all of them, and none have any problems reading other discs; so I don't think this is the issue.

3 - The brand in this case is Kodak; I sometimes use Verbatim also, but never no-name, £10-for-a-cake-of-100 jobs. I always look for pthalocyanine dye discs (yellow recording surface), not azo (blue), as the research I've come across (e.g. this) suggests that it is fundamentally more stable.

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ok, thought about it some more

this CD recorder of yours, according to online specification, has digital out - so you can play back the affected disk in it, and transfer direct digital from this recorder, if you're lucky, into the digital-in socket of your soundcard, no analogue degradation then

however, your soundcard probably doesn't hjave this, so you need to find one that does - about £20 I believe

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Many thanks folks. Spot: yes, this is the final option. However, the CD recorder doesn't have a digital (SPDIF or optical) output, meaning that I'd have to transfer the audio via analogue, thus causing signal degredation in the two lots of conversion.

blimey, ok then, internet spec said different, but you must be right as you have the thing!!!

**** you could seek out another CD player, as in a normal domestic separates CD player, one with a digital output, preferably a philips, but try any, and see if any of these play the disk, and then do the digital transfer from there ?? **** (this is getting silly now of course)

In answer to Si1:

3 - The brand in this case is Kodak; I sometimes use Verbatim also, but never no-name, £10-for-a-cake-of-100 jobs. I always look for pthalocyanine dye discs (yellow recording surface), not azo (blue), as the research I've come across (e.g. this) suggests that it is fundamentally more stable.

I feel almost humbled!!!???!!!

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I know this isn't any immediate help

but in my experience all forms of CD / DVD can be extremely unreliable.

I therefore always make two copies of everything I archive and make sure both copies read back correctly before deleting any originals.

Anyone who has valuable data saved on only 1 cd/dvd should make duplicate copies as having only 1 copy is asking for trouble.

I have no idea why, but it seems hellishly difficult recovering data from corrupted disks without, as you say, purchasing expensive software which more often than not, doesn't work.

Fortunately cd/dvds will be replaced ny solid state storage ie memory cards in the not too distant future.

But then again it will still be wise to have 2 copies of important data.

:)

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Many thanks again.

Sorry, I should have been clearer. The CDR-870 does have an optical digital output, but it is encrypted using the Serial Copy Management System. This is a bit like a primitive version of HDCP: the device on the other end of the cable has to 'handshake' with the CDR to tell it that it is not trying to record the digital audio stream, only decode it for playback through loudspeakers. No handshake, and the CDR won't output any digital audio. My sound card won't handshake with it. What I actually meant was that 'digital output from the CDR isn't an option', but couldn't be bothered to bash out the geeky details!

I know this isn't any immediate help

but in my experience all forms of CD / DVD can be extremely unreliable.

Agreed completely, and I don't use them for long-term data preservation either. According to that report I posted a link to above, the biggest disc killer is light; and therefore, storing them in a totally dark environment (e.g. a filing cabinet) is the biggest thing you can do to preserve them. But even then we're only talking about the difference between five years and ten, even in the case of so-called archival media (e.g. MAM-A) that claim to have a shelf-life of centuries. The bottom line is that the recording medium is a dye, and that dyes are affected by light, whatever you're doing with them. Just as the floral pattern on your curtains will fade over years of them being drawn in bright sunlight, so will the recorded data on a recordable CD, DVD or BD.

I'm rapidly coming to the conclusion that it's time to invest in a decent sound card and capture directly.

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But even then we're only talking about the difference between five years and ten, even in the case of so-called archival media (e.g. MAM-A) that claim to have a shelf-life of centuries. The bottom line is that the recording medium is a dye, and that dyes are affected by light, whatever you're doing with them. Just as the floral pattern on your curtains will fade over years of them being drawn in bright sunlight, so will the recorded data on a recordable CD, DVD or BD.

it's interesting - the engineering basis for optical CD storage (and I guess those later standards derived from it) were not, apparently for archiving - were instead for music storage (which in itself is robust since a few errors don't matter due to internal algorithms to fill in missing data, ok so not bit-identical but most of us don't notice the difference); and then also for large scale data storage, but not necessarily archiving

as far as I know, hard drive based archive systems ALWAYS use some kind of parity/striping system to create redundancy across media, even tho the media is pretty reliable

why oh why anyone would use a non-striped/parity back up system on a system (optical) that was designed from the bottom up for something else, is somewhat beyond me - looks like it is asking for trouble

only reason the manufacturers CLAIM they can be used for archiving is surely to drum up business, and business that is not correlated with existing sales at that

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Make an image of the disk using Nero, dd, some other tool. Work on that image and not the original disk.

Use isobuster and click make it so when it complains that image is crap.

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  • 312 Brexit, House prices and Summer 2020

    1. 1. Including the effects Brexit, where do you think average UK house prices will be relative to now in June 2020?


      • down 5% +
      • down 2.5%
      • Even
      • up 2.5%
      • up 5%



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