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vinyl versus digital redux

Has anyone compared the sound of vinyl with the sound of digital converted from a vinyl intermediary ?

I am referring to 'rips' of vinyl made with high end, high quality vinyl playback systems, with
conversion to high resolution digital.
I find it nearly impossible to distinguish the two results.
The digital rip of a vinyl record sounds identical...or very nearly so...to direct playback of the vinyl.

If one has 'experienced' the foregoing, one might question why digital made without the intermediary of vinyl sounds so different from vinyl.   A detective story ?

We are talking about vinyl made by ADC (analog to digital conversion) of an amplified microphone signal and re-conversion to analog for output to the record cutting lathe, or from analog tape recording of an amplified microphone signal, and then....as above...via ADCl and back to analog for output to the cutting lathe.

Of course vinyl can be and is 'cut' (pressings made from 'stamper' copies the 'master' cut in lacquer) without digital intermediary.  Such practice is apparently uncommon, and ?? identified as such by the 'label' (production)

Has anyone compared vinyl and high resolution digital (downloads) albums offered by the same 'label' of the same performance ?  Granted, digital versus vinyl difference should diminish with higher digital resolution.   Sound waves are sine waves....air waves do not 'travel' in digital bits.    A digital signal cannot be more than an approximation of a sine wave, but a closer approximation as potential digital resolution (equating to bit depth times sampling frequency) increases.

If vinyl and digital well made from vinyl intermediary sound almost identical, and If vinyl and digital not made via vinyl intermediary sound quite different, what is the source of this difference ? 

Could it reside....I'll skip the sound processing stages (including RIAA equalization)...in the electro-mechanical process imparting the signal to the vinyl groove ?

Is there analogy with speaker cone material and the need for a degree of self-damping ?
Were self-damping not to some extent desirable, would not all speaker cones, from tweeter to sub-woofer, be made of materials where stiffness to weight ratio was of sole importance ?

Thanks for any comments.
seventies

Showing 7 responses by atmasphere

atmasphere's avatar
atmasphere
12,138 posts
 
Analog tape is not a panacea. Just like vinyl, it significantly colors the sound.
To be clear, analog tape colors the sound more than the LP, owing to the fact that a properly functioning tape machine will exhibit a 3rd harmonic, which contributes to 'bloom' and apparent detail.
atmasphere's avatar
atmasphere
12,138 posts
 
Atmasphere! I have two original copies of It's a Beautiful Day! I loved it so much I bought another copy worried I would play the one to death.
Finding the original Columbia of that is no easy task. It sounded great, and people played them to death. I found an original European copy that is excellent; never found the original American in decent condition. I stopped looking years ago- the European press is far better than any of the later American pressings. I usually have this LP with me when I do shows, since so many people have heard it.  I've been accused of cheating by playing LPs like this, but heck, if your software doesn't sound good neither will your stereo.
atmasphere's avatar
atmasphere
12,138 posts
 
What is wrong with electricity? If it were not for electricity we would not be having this conversation.
 I think you lightly dismiss digital storage. With digital storage backups are always a necessity.
:) My objection is having to use electricity to maintain the recording itself. Its nice that the recordings can sit on the shelf and sound the same ten years from now as they do now. Having worked for a while in the computer industry (albeit a long time ago) I do admit that I'm a bit distrustful of digital storage. But don't mistake that for being dismissive- I really appreciate the physical space and convenience. Digital has gotten good enough that if I had to start over, I'd probably not be so concerned about having vinyl. But OTOH have some LPs that simply won't ever get to be reissued from the masters as they are gone (ex.: Its A Beautiful Day famously burned the master tape to their best LP during a dispute with the label).
atmasphere's avatar
atmasphere
12,138 posts
 
As for tape degradation, the SSS (sticky shed syndrome) was a major problem on Ampex 406/407, 456/457, scotch 226/227, and a few others.

After Quantegy stated they had fixed the binder problem I bought 4 new cases of 456 with the new and improved binder. They were good for the first few years, but after that they slowly degraded into sticky shed just like the earlier stuff. Ended up pulling the flanges off and tossing the balance of the remaining tape into the trash.
I bake tape for about 3 hours at 140-150 degrees if there's any question about age or storage (and these days there usually is). This will cause the moisture to exit the tape and it should be good for a few months. It helps to store the tape in a plastic bag with a packet or two (more if its 1/2" or 1" tape) of silica gel to absorb moisture. Its better to store the tape in the attic rather than the basement! We remastered an LP where the artist ('Spider' John Koerner) did exactly that and the tapes (recorded in the early 1970s) were immaculate- no shedding and no need for baking.
it is my understanding that most of the old tapes have been digitized. Correct me if I am wrong but digital storage is certainly more robust. Once in numbers that "sleepiness" can be corrected with very modest EQ as well as doing neat stuff like getting rid of the tape hiss.
Some tapes have been digitized. Many, possibly most are missing because studios sold them off or sent them to landfill. Digital storage is less robust than LP, unless the digital storage is constantly moved/backed up (which means electricity is involved for the period in which the recording is stored); if analog tape is stored properly (see above) it can last decades, but its rarely treated properly. You can't correct that 'sleepiness' with just EQ; you need a bit of expansion (as opposed to compression) and you can't do anything about the loss of detail. This is all why original LPs are usually the best 'record' (if you'll pardon the term) of an older musical event.
This is according to research done by the Library of Congress when deciding upon their long term archive needs.
That study was done sometime in the 1980s if memory serves. What they found was that laminated media (magnetic media and CD) had lifetimes in decades if stored properly (months or years if not) but amorphous media (LPs and the stampers that made them) could last centuries. The study did not include any kind of solid state media like thumb drives.


atmasphere's avatar
atmasphere
12,138 posts
 
Atmasphere, what is wrong with digital signal processing assuming it is used correctly? I know it is easy to screw things up, done correctly.
Its easy to screw up is all! I prefer a minimalist approach, using as little as I can. The more DSP gets into the mix, the more it seems to harm the final signal. But my experience with DSP is limited to its used in recording applications.
Does playback (with or without digitization) of lp's made, say 40 years ago, from audio tape offer advantage over hi res digital transfers made today from those 40-year-old tapes ?
@seventies
Of course! Tape degrades from the day it was recorded. If you want the best sounding LP from tape, you cut the LP ASAP. You then have the lacquer plated ASAP- that's how you get a lively vivacious recording. If you wait 40 years, no matter what method you use, the master tape will sound a bit 'sleepy' compared to the day it was recorded!
Analog tape is surprisingly robust for storage. It is usage that degrades it.

@audio2design
This statement is false unless very special care is taken in storage which is quite rare! If the tape is polyester, it is prone to absorbing moisture which leads to shedding; trust me on this if a tape has gone too far you won't even be able to spool it off the reel. Think: goo
I am asking about LP's made decades ago from analog tape...whether these lp's preserve sound...particularly high frequency sound...better than does the tape itself.
Yes. LPs have a lifespan of nearly a century if stored correctly (normal humidity and temperature, upright, not too many on a shelf). Stereo LPs have bandwidth to 40KHz or so, tape does not.



atmasphere's avatar
atmasphere
12,138 posts
 
@mijostyn   Its funny how much better a master digital file is than one that's been exposed to DSP!
atmasphere's avatar
atmasphere
12,138 posts
 
Hm. One thing I don't see mentioned here is the issue of bandwidth. Any LP made since the dawn of the stereo era (1958) has potential bandwidth to over 40KHz. Bandwidth during playback has been in that realm for a while too- most phono preamps have bandwidth on the RIAA de-emphasis curve that goes well beyond 20KHz! We spec ours to 100KHz. Most phono cartridges made since about 1970 or so have no worries going to 40KHz and MC cartridges can go much higher. In a nutshell the LP is apparently the widest bandwidth format available.


Now I know there isn't anything up there but probably noise and distortion. But there is also the issue of phase shift, and that is interpreted by the ear as a tonality. Phase shift exists whenever there is a filter; over the broadest spectrum if 6db per octave (going to 10x or 1/10 the frequency of the cutoff, depending on whether its a low frequency or high frequency cutoff) and less spectrum with increasing orders, although more phase shift as you approach the cutoff frequency.


I notice the difference between analog and digital right away; so does my girlfriend; its not hard to hear. I've not done research but I suspect that bandwidth thing has been ignored in this ongoing...  - thing.



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