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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
atmasphere's avatar
atmasphere
11,784 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.



audio2design
1,351 posts
 
A master clock only attempts to compensate for design deficiencies that may exist in a playback system. With USB DACs or networked DACs, and half decent electronics, there is little requirement for them in most cases.

Analog tape is not a panacea. Just like vinyl, it significantly colors the sound.I think part of the problem is that even though so many audiophile talk about "real" or "natural" sound, very few have heard what most instruments sound like not when not colored by the environment, absent of the influence of other instruments, when recorded closely, etc. Even musicians who play regularly are sometimes surprised to hear how they sound recorded. Live orchestra is heavily influenced by seating position and hall design and mood. Perhaps what most audiophiles, most of who are older, consider natural or realistic, is not natural or realistic, but familiar?

A nice discussion of tape, and tape plug ins for digital work flows that emulate tape sound:https://www.uaudio.com/blog/analog-tape-recording-basics/

Most digital is oversampled on recording and upsampled on playback. Phase shift will be minimal in the audio band and much less than vinyl. Historically magnetic tape either had bandwidth on the top end or bass on the bottom end. Those classic vinyl releases off analog tape were based on a source with limited bandwidth themselves no matter what a playback system was capable. If people could hear anything past 20Khz, I suspect poor channel matching in vinyl setups would drive them batty.  I notice the difference too between analog sources and digital. One done in a reasonable fashion sounds exactly what is coming off the microphones. One does not.
emrofsemanon's avatar
emrofsemanon
292 posts
 
i have never, even on megabuck equipment, heard the best specimen LPs sound subjectively and objectively "better" [less distorted/changed greater dynamic and frequency range], than i have on the best digital. that said, i've heard lots of bad digital. and lots more of bad analog. furthermore i never understood how some reviewers of Lp recordings can describe "silent surfaces" as i ALWAYS hear some surface noise even on a virgin pressing. 
johnss
569 posts
 
The other comment I forgot to add, is regardless of the digital sampling freq. and bit depth,  most commercial recordings released on digital use quite a bit of compression in the signal chain, which is sad. One of the main advantages of digital, especially hi rez files is super wide dynamic range. If you need proof, just play your favorite CD or digital file, while feeding the signal to a set of VUs and watch for the minimum and max change in level.  With most digital recordings, there is not much there. It is a shame since with higher rez formats, the dynamic range available is seldom used. 

The comments about  master clocks not needed if the electronics are done correctly is mis-information; or not correct. All you need to do is step into any modern studio and you will find most of the A to D devices and recorders are run by a master clock of some sort. Same applies to playback. But most have not heard the improvement a clock can make since majority of consumer oriented DACs do not have an external clock input.

All of the above applies to 24/96 and higher rez. If you are listening to 16/44.1 files, even inexpensive analog will usually blow these data rates away.

Several years ago, I was asked to do a recording for a major suburban audiophile club to allow them to hear the analog/digital comarison. They had 2 performers, a singer/ guitar player and bass player.

I set up with both high rez digital, and 30 ips analog tape. Stereo X/Y pair fed to microphone preamps. The signal from the preamp was split, one side went to A to D, the other side to the analog tape inputs. I could feed any of the three signals to the headphone amp and 2 pairs of Senn HD800s. The listener could select between the live mic feed, the signal coming off the tape, or the output from the A to D/ D to A converter. Most were shocked they could not hear a difference between the live feed and the signal off the tape, but could hear a difference between the live mic feed and the output from the converter. 

seventies OP
67 posts
 
emrofsemanonm audio2design, atmasphere and others
Hard to disagree with any of your statements.
Regarding phase shift and other 'distortions' more prevalent in vinyl than digital recording, electro-mechanical lathing/playback (with RIAA equalization) seems of central importance.
Regarding potential frequency response with vinyl, again no argument.
This frequency response....higher frequency reproduction...is I would argue better preserved by playback (with or without subsequent digitalization) of vinyl pressings contemporaneous with the original recording than by 'master tapes' of those recordings, because of time-dependent degradation of the tapes. 
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