How'd they go from tape to CD in the begining? at DVinfo.net

Ben Gurvich · March 25th, 2006, 05:01 AM

Im wondering how they went from professional audio tape to Compact Disc in the early 80's?

Obviously they didnt have a 700mb hard disc at that time. I have looked around on the web and can find plenty on the manufactiring process but nothing on the encoding process.

My guess is they had to do the conversion in real time thru an A/D convertor which would then burn the pits then and there.

Another possibility is that they could capture a second at a time from tape and then digitize it, but this seems it would have sync problems.

I was also interested in the format they recorderd in. Did they just have a chip at either end converting the binary data into sound ie. on off on on off = 18,000khz.

Anyway, im sure someone on here will know the answer to this retro question.

Cheers,
Ben Gurvich

Barry Gribble · March 25th, 2006, 07:19 AM

Ben,

I used to produce CD-ROMs in the days before CD-R's and we delivered the masters on 8mm digital tapes. Obviously at that point we did have the hard drives that could handle the masters (it was 1990 or so). I believe that even in the earlier 80's the mastering facilities that were laying out North of a million dollars for the mastering lathes could cobble together a hard drive (or bank) that held the data. It was just far beyond the reach of a consumer.

Recording directly to the bits on a CD is actually impossible because the CD-Audio format has a strong amount of error-correction coding in it. You can actually draw an 1/8 inch line along a radius of the data side of a CD and it will still play fine - even though the line is covering thousands of bit on each pass. This is part of the reason CD-Audio discs only hold 72 minutes of data.

CD's have always been 44.1 KHz sampling.

Just a funny retro note - when the CD-R's first rolled out in the professional arena the drives were running $15k and the discs were on the order of $35.

John C. Chu · March 25th, 2006, 07:40 AM

I think I remembered a digital encoder/decoder that recorded the digital bits to VHS tape.

The data stream was just encoded as a "video" type signal.

You also played back the recording thru this magic box.

Ben Gurvich · March 26th, 2006, 03:37 AM

So, they used a tape back up drive to convert the audio masters into digital, and then went from there? That sounds like theyre gettting the A/d conversion out of the way, and then worrying about the transfer of data from tape to cd after lunch, still not quite sure though.

I remember when those cd recorders came out. Its inersting that dvd writers came out years after dvd , same as with cd. But Blu ray and HD DVD are giving it upfront.

Obviously they can make more money this way

Emre Safak · March 26th, 2006, 09:03 AM

Quote:

Originally Posted by Ben Gurvich

I remember when those cd recorders came out. Its inersting that dvd writers came out years after dvd , same as with cd. But Blu ray and HD DVD are giving it upfront.

And not a moment too soon! Lots of people are already shooting HD, and they don't know where to store it.

John C. Chu · March 28th, 2006, 02:32 PM

Quote:

Originally Posted by Ben Gurvich

So, they used a tape back up drive to convert the audio masters into digital, and then went from there?y

I dunno if this is how they did it back then...

http://www.proaudioreview.com/may00/...eviewWeb.shtml

J. Stephen McDonald · April 1st, 2006, 11:25 PM

Quote:

Originally Posted by John C. Chu

I think I remembered a digital encoder/decoder that recorded the digital bits to VHS tape.

The data stream was just encoded as a "video" type signal.

You also played back the recording thru this magic box.

I saw a guy on a PBS monkey show about 15 years ago, who had a multi-tracked pro digital audio recorder, with a big parabolic mike. It recorded on BetaCam SP video tapes. Anyone know what make or model this might be? I wish I had an audio rig like this.

David Sheneman · April 5th, 2006, 08:07 AM

Quote:

Originally Posted by John C. Chu

I dunno if this is how they did it back then...

http://www.proaudioreview.com/may00/...eviewWeb.shtml

I've done a lot of reading on both the consumer and professional side of audio in the last 20 years I've been a church sound guy. I have heard of this PCM-F1 processor the article talks about before because I used to have a Sony VHS VCR that was supposed to be a good match for it - at least it was mentioned as an option in the manual - perhaps they just put that in all of their VCR manuals for a while, but it was one of Sony's first VHS VCRs and it was a quite expensive and capable deck at the time.

One of the other things I read years ago in relation to this topic is that for the first several years (probably 10 or more) every music CD that was mass-produced was mastered using a Sony 3/4" (U-Matic) VCR. This processor mentioned above was obviously meant to be a lower-cost version of what the big mastering houses were using when "affordable" CD production was getting started. I wish I could remember the source of the article or more of the details, but I've read so much over the years that I think I forget more every day than I learn.

Related Trivia Question: Does anybody know what the first CD ever released was? And no googling allowed!

Gary Chavez · April 6th, 2006, 01:38 PM

Beathoven's 5th?
I think thats why CD are the lenght they are, correct?

Jack Zhang · April 7th, 2006, 12:15 AM

This is sounding too much like "Which came first? The Chicken or the Egg?".

David Sheneman · April 7th, 2006, 08:09 AM

Quote:

Originally Posted by Gary Chavez

Beathoven's 5th?
I think thats why CD are the lenght they are, correct?

Nope. Billy Joel's 52nd Street.

March 25th, 2006, 05:01 AM	#1
Ben Gurvich Major Player Join Date: Dec 2003 Location: Australia Posts: 329	How'd they go from tape to CD in the begining? Im wondering how they went from professional audio tape to Compact Disc in the early 80's? Obviously they didnt have a 700mb hard disc at that time. I have looked around on the web and can find plenty on the manufactiring process but nothing on the encoding process. My guess is they had to do the conversion in real time thru an A/D convertor which would then burn the pits then and there. Another possibility is that they could capture a second at a time from tape and then digitize it, but this seems it would have sync problems. I was also interested in the format they recorderd in. Did they just have a chip at either end converting the binary data into sound ie. on off on on off = 18,000khz. Anyway, im sure someone on here will know the answer to this retro question. Cheers, Ben Gurvich

March 25th, 2006, 07:19 AM	#2
Barry Gribble Major Player Join Date: Aug 2003 Location: Los Angeles, CA Posts: 817	Ben, I used to produce CD-ROMs in the days before CD-R's and we delivered the masters on 8mm digital tapes. Obviously at that point we did have the hard drives that could handle the masters (it was 1990 or so). I believe that even in the earlier 80's the mastering facilities that were laying out North of a million dollars for the mastering lathes could cobble together a hard drive (or bank) that held the data. It was just far beyond the reach of a consumer. Recording directly to the bits on a CD is actually impossible because the CD-Audio format has a strong amount of error-correction coding in it. You can actually draw an 1/8 inch line along a radius of the data side of a CD and it will still play fine - even though the line is covering thousands of bit on each pass. This is part of the reason CD-Audio discs only hold 72 minutes of data. CD's have always been 44.1 KHz sampling. Just a funny retro note - when the CD-R's first rolled out in the professional arena the drives were running $15k and the discs were on the order of $35. __________________ Barry Gribble Integral Arts, IMDB

March 25th, 2006, 07:40 AM	#3
John C. Chu Major Player Join Date: Sep 2003 Location: Rego Park , NYC Posts: 665	I think I remembered a digital encoder/decoder that recorded the digital bits to VHS tape. The data stream was just encoded as a "video" type signal. You also played back the recording thru this magic box.

March 26th, 2006, 03:37 AM	#4
Ben Gurvich Major Player Join Date: Dec 2003 Location: Australia Posts: 329	So, they used a tape back up drive to convert the audio masters into digital, and then went from there? That sounds like theyre gettting the A/d conversion out of the way, and then worrying about the transfer of data from tape to cd after lunch, still not quite sure though. I remember when those cd recorders came out. Its inersting that dvd writers came out years after dvd , same as with cd. But Blu ray and HD DVD are giving it upfront. Obviously they can make more money this way

April 6th, 2006, 01:38 PM	#9
Gary Chavez Major Player Join Date: Mar 2003 Location: San Antonio Posts: 355	Beathoven's 5th? I think thats why CD are the lenght they are, correct?

April 7th, 2006, 12:15 AM	#10
Jack Zhang Inner Circle Join Date: May 2005 Location: Burnaby, BC, Canada Posts: 3,053	This is sounding too much like "Which came first? The Chicken or the Egg?".