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How much did ADCs in the 80s affect the sound quality of CDs?

VientoB

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A lot of people like to purchase older CDs of their favourite albums since they tend to have better dynamic range and are perceived to sound better than newer masterings. But are there distortions that the older ADCs used to create the digital masterings back in the 1980s that would be (1) measurable and (2) audible?
 
A lot of people like to purchase older CDs of their favourite albums since they tend to have better dynamic range and are perceived to sound better than newer masterings. But are there distortions that the older ADCs used to create the digital masterings back in the 1980s that would be (1) measurable and (2) audible?
Can't tell or know the effects on ADC's in the 80ties. What i think to know why first release CD's could be interesting because they could retain transients that are lost over time on original analog mastertapes. Here under an interview with Roger Nichols recording Engineer from Steely Dan on loss of transients already in hours :facepalm: Besides that lot of CD's in the 80ties used the vinyl master which has lots of limitations one of the reasons that quite some CD's didn't sound well from that time.


Part of the Nichols interview:

Roger Nichols: Yes, and it’s mostly because when I record something on a digital machine..um, you know, and I play it back ten years from now it will sound exatly the same. So if there is some little artifact because it’s digital, it’s a majorable (sic) artifact, and it’s going to be the same artifact ten years from now. If I record something on Analog tape and it doesn’t matter whether I’m do using Dolby SR, Dolby A or DBX or no noise reduction or whatever it is, if you record something on a piece of analog tape and play it back later the same day, the same program is not on the tape. And there’s nothing so far that anybody’d been able to do about that, you know, like those little magnetic particles are made to be able to wander around and they do so by themselves while the tape is just sitting there. I’ve made DAT copies when I’m cutting tracks, and then have an automation snap shot of the mix and then later that evening put the tape back on, play it back, compare it with the Dat, and there’s already starting to be a difference. And by the time a week or two weeks go by and it’s time to mix, a lot of the transients have started to disappear. If you use this as a tool, some people like what this does, and it sort of helps to mix all their music together, that’s fine, but, you know, you can’t say that Analog tape with Dolby SR is as good as Digital. It might be as quiet, and but it’s not going to retain the signal, you know, as long as Digital tape. So that’s my biggest worry about Analog tape.
 
A lot of people like to purchase older CDs of their favourite albums since they tend to have better dynamic range and are perceived to sound better than newer masterings. But are there distortions that the older ADCs used to create the digital masterings back in the 1980s that would be (1) measurable and (2) audible?
It's a great question. Professional ADCs and DACs were expensive and (compared to domestic equivalents at the time) relatively high performance.

However, they almost certainly were not perfectly linear across all 16 bits and may not have had extraordinarily accurate and consistent clocks.

Can you measure it? Not on commercially released music, since the consequences of non linearity and/or clock drift or clock jitter will be baked in.
 
It's a great question. Professional ADCs and DACs were expensive and (compared to domestic equivalents at the time) relatively high performance.

However, they almost certainly were not perfectly linear across all 16 bits and may not have had extraordinarily accurate and consistent clocks.

Can you measure it? Not on commercially released music, since the consequences of non linearity and/or clock drift or clock jitter will be baked in.
I supposed you'd need to do a comparison using one of those old ADCs and a modern one on the same master tape.
 
Can't tell or know the effects on ADC's in the 80ties. What i think to know why first release CD's could be interesting because they could retain transients that are lost over time on original analog mastertapes. Here under an interview with Roger Nichols recording Engineer from Steely Dan on loss of transients already in hours :facepalm: Besides that lot of CD's in the 80ties used the vinyl master which has lots of limitations one of the reasons that quite some CD's didn't sound well from that time.


Part of the Nichols interview:

Roger Nichols: Yes, and it’s mostly because when I record something on a digital machine..um, you know, and I play it back ten years from now it will sound exatly the same. So if there is some little artifact because it’s digital, it’s a majorable (sic) artifact, and it’s going to be the same artifact ten years from now. If I record something on Analog tape and it doesn’t matter whether I’m do using Dolby SR, Dolby A or DBX or no noise reduction or whatever it is, if you record something on a piece of analog tape and play it back later the same day, the same program is not on the tape. And there’s nothing so far that anybody’d been able to do about that, you know, like those little magnetic particles are made to be able to wander around and they do so by themselves while the tape is just sitting there. I’ve made DAT copies when I’m cutting tracks, and then have an automation snap shot of the mix and then later that evening put the tape back on, play it back, compare it with the Dat, and there’s already starting to be a difference. And by the time a week or two weeks go by and it’s time to mix, a lot of the transients have started to disappear. If you use this as a tool, some people like what this does, and it sort of helps to mix all their music together, that’s fine, but, you know, you can’t say that Analog tape with Dolby SR is as good as Digital. It might be as quiet, and but it’s not going to retain the signal, you know, as long as Digital tape. So that’s my biggest worry about Analog tape.
I wonder if that's true or in his imagination.
 
I supposed you'd need to do a comparison using one of those old ADCs and a modern one on the same master tape.
Yes, that's the challenge. I worked on professional ADCs before and after the earliest CDs. They were good, but modern equivalents are spectacular in terms of linearity and clock accuracy and jitter.

There can be other issues with early CDs such as a lack of dither or incorrect metadata for preemphasis.
 
I wonder if that's true or in his imagination.
"and then later that evening put the tape back on, play it back, compare it with the Dat, and there’s already starting to be a difference."
Thats an A/B comparison by one of the best recording engineers on the planet, don't think its his imagination.
 
"and then later that evening put the tape back on, play it back, compare it with the Dat, and there’s already starting to be a difference."
Thats an A/B comparison by one of the best recording engineers on the planet, don't think its his imagination.
Unless he controlled for levels and didn't know which was which he is subject to the same problems of uncontrolled listening as every other human.
 
Besides that lot of CD's in the 80ties used the vinyl master which has lots of limitations one of the reasons that quite some CD's didn't sound well from that time.
I think this is more myth than truth. They were still doing cassette tape, and even some RTR releases. Those would not use the vinyl master so the idea CDs did just does not add up.
 
"and then later that evening put the tape back on, play it back, compare it with the Dat, and there’s already starting to be a difference."
Thats an A/B comparison by one of the best recording engineers on the planet, don't think its his imagination.
It's not a blind A/B comparison. We know how the brain can be fooled.
 
Not at all, as far as I can tell. The ADCs of the 1980s were totally transparent even then albeit well down on current measurements. CD has been 'pure, perfect sound' since 1983, as far as the technical performance.

S
They had flat frequency response, they had distortion below -80 db sometimes -90 db, and SNR of 90 db. They would have low level linearity that was less than great. I doubt the speed issues or jitter was a problem. Some early models used a sample rate of 44,056 rather than 44,100. So I think you are right they would have been transparent or awfully close.
 
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I think this is more myth than truth. They were still doing cassette tape, and even some RTR releases. Those would not use the vinyl master so the idea CDs did just does not add up.
Steven Wilson also famous for his remasters Yes etc etc is always asking for the original master not the Vinyl master which he calls the do not use master. But yes it is difficult to know which cd is using the Vinyl master. But why do you think that cassets and or RTR tape not using the Vinyl masters?. As far as i know the vinyl master is a analog tape tape masterd such is take care of the dynamic Vinyl limitations. Could also be used for cassette or RTR tape.
 
Steven Wilson also famous for his remasters Yes etc etc is always asking for the original master not the Vinyl master which he calls the do not use master. But yes it is difficult to know which cd is using the Vinyl master. But why do you think that cassets and or RTR tape not using the Vinyl masters?. As far as i know the vinyl master is a analog tape tape masterd such is take care of the dynamic Vinyl limitations. Could also be used for cassette or RTR tape.
Because having back in those days compared CD, tape and vinyl, all I could find the basic balance was the same or very similar on all of them while vinyl was always very different. I couldn't say it never happened, but among my friends we were able to listen to a fair sampling and every time the vinyl was the odd man out.
 
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