Has anyone been able to define well or measure differences between vinyl and digital?

@thespeakerdude

If there is any interest, this is probably the best single article I have discovered that explains digital audio. It is not light reading nor heavy reading. Dan, who put it together obviously put a lot of time into it. It is almost 20 years old so comments about processing power are no longer relevant, but everything else is. I have come across many articles on digital audio written by less technical people. They get the basics right, but they often make mistakes and they never go into the depth that this article provides. You may need to read it 2 or 3 times to understand well enough, but if you do, it will dispel a lot of misconceptions about digital audio.

https://lavryengineering.com/pdfs/lavry-sampling-theory.pdf

If you have any questions about the article I will try to answer them.

Thank you for referring this document. Oldie but goodie. Excellent for illustrating the older paradigm vs newer paradigm.

Let’s look at the graph there marked with "Let us begin by examining a band limited square wave". That’s what I meant by saying that quickly changing signals start looking ragged when band limited. The document goes into a detailed explanation of why this is happening. For a briefer explanation, one can peruse a Wikipedia article about Gibbs Phenomenon.

Note that what we see on a square wave is an extreme example. The underlying mechanism of the Gibbs Phenomenon is in action on any harmonic signal with changing magnitude - just to a lesser degree, depending on ratio between characteristic time of the harmonic components magnitude change and sampling interval.

The concentrated difference between the older and the newer paradigm is this:

Subscribers to the old paradigm believe that the wiggles we see on charts like that don’t ever affect perception of sound quality, as long as the signal to be band-limited is "music", and the upper boundary is set at 22 KHz.

The new paradigm tells us that it depends. That certain wiggles may affect perceived sound quality of certain music signals band-limited under the conditions above, for certain listeners.

By the way, 0.1% THD corresponds to a width of one pixel on a typical laptop display, if a graph like that is enlarged to fill the whole screen.

Basically, we can hear a difference that we can barely see on a graph.

If one sees any visual difference of a band-limited music signal compared to the original one, this should arise strong suspicion that such difference may be heard.

However, my professors, from leading European universities, and their teaching assistants, had other opinions, giving me straight As on all courses related to Fourier Analysis and DSP.

Call me skeptical. No that is not right. I flat out don’t believe you are telling the truth.

Yet there is more, which came mostly from research conducted by others over past three decades. Unfortunately, too much of it is still widely dispersed in numerous peer-reviewed papers, rather than concentrated in a few engineering handbooks.

Well isn’t that convenient. Hate ta break it to ya but I learned all the theory in an applied math course. Because little of this has to do with engineering. It’s applied math.

This depends greatly on the nature of the band-limiting filter used.

That is totally irrelevant to what you replied to.

Implemented with analog circuitry, yes. But, at some point inside a class-D amp analog signal is transformed into a sequence of discrete +V and -V segments, starting and ending at analog time boundaries.

Wrong. Very wrong.

 

for some mysterious reasons, want to use digital formats providing higher information density.

For processing not delivery just like I said

(e.g. I own several nice 32/768 ADC/DACs),

No such thing as a 32 bit ADC or DAC. Purely a data standard ... And a marketing ploy. Maybe you will find some rounding errors in those bottom 8-9 bits.

By the way, 0.1% THD corresponds to a width of one pixel on a typical laptop display, if a graph like that is enlarged to fill the whole screen.

I am only storing that last paragraph for posterity.

Shhhh don’t tell anyone, but vinyl is terrible at <20hz and pretty awful in practice >20khz .... But I can’t hear it so I don’t care

If anyone cares my patience is officially at an end :-)

Nyquist is not a paradigm or a guess about how things work. It is not about engineering. It is a well understood, well researched, to this point not disproven mathematical theory. Nothing in the last 30 years has changed that. How it is applied is also well understood including translating real world limitations to accuracy. Those are not engineering principles, they are math principles.

This has been one of the deepest technical discussions I’ve read on Audiogon. Thanks to Fair and TheSpeakerDude for sharing their viewpoints here.

I watched the video posted earlier to explain digital and that helped me to understand some of these recent expositions.

@Fair can you summarize on this issue?

@johnread57 ,

I did not present an opinion. I presented verifiable, researched, well understood, mathematical facts. Facts not disputed by those with the deepest understanding of the underlying math, and those able to adapt the math to practical implementation.

Below is an opinion. It misinterprets personal opinion, narrow market popularity, and different to "something". That something is only described in easily falsified claims, falsified with math, not an appeal to narrow market popularity.

Perhaps @Fair, can enlighten with at least 2 or 3 of these research papers he claims are hard to find? A new paradigm with 3 decades of research that legitimately calls into question all current signal processing and hearing knowledge should have many available sources to reference.

I see it differently. The old paradigm is falsified by phenomena for which it gives invalid predictions. For instance, according to the old paradigm, LPs shall be long gone, the way of cassette tape recorders and VCR video tapes. Yet LPs persisted, and the classic paradigm produces no convincing explanation as to why.