 
|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
|
|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
137.69.85.36
In Reply to: Re: Still off base.... posted by MusicLover on September 26, 2005 at 14:47:55:
It doesn't really matter if there is or isn't any signal above 20kHz.You can't implement a 22kHz filter (needed for anti-aliasing) that doesn't effect frequencies much lower than that. It's one of those weird conceptual things, but even a 100kHz filter will have an effect way down at 20kHz (although it's small).
I can recommend some things to read if you would like to learn more abou analog filters.
To answer your last question: I believe that there is some digital encoding/decoding scheme that will beat vinyl in its traditional areas of strength, while building on CD's strengths, but 44.1/16 isn't it.
Based on my experience and reading, it appears to be somewhere up above 96/24......
I'm not anti-digital, but it's clear that "perfect sound forever" was a marketing lie. We just aren't there yet.
Peter
Follow Ups:
OK. THanks.
I disagree with you about the vinyl groove encoding scheme being superior to redbook, becuase, based on my understanding, vinyl groove encoding has much more distortion of the original waveform ( i remember reading somewhere it was 3-4%).
Hence my conclusion, that while vinyl lovers may LIKE this, it's certaily inferior to redbook.
AS i have said before, I like SET amps, but I accept that they suck performance wise.
Anyways, thanks for your posts. I actually learned something, which is very very rare on the asylum.
ML
Two thoughts about your distortion comment:
(I'm not arguing for the sake of it; it's a fascinating subject)Don't downplay your love of SETs; they might actually be technically superior... :-)
Vinyl's distortion characteristic is indeed similar to the SET in 2 important respects. First, the distortion tends to be dominated by low order harmonics, which are less audible than the high order distortion generated by amps that use feedback. Did you know that several percent of 2nd harmonic is virutally inaudible, while 1 percent 7th harmonic would sound terrible?
Secondly, I would guess that the distortion decreases with signal level, so low-level musical details might actually be reproduced with v.v.v low distortion.
Think about digital; it's the opposite. A digital system has the lowest distotion at maximum output. As the level goes down, the number of bits available also decreases, so the distortion goes up.
That COULD mean that low-level musical details are actually reproduced with v.v. HIGH distortion.
So, you see that this is an interesting technical onion that has layers of subtlety. Simplistic statements of clear superiority for digital are pretty risky...
Peter
> > > Think about digital; it's the opposite. A digital system has the lowest distotion at maximum output.
> > > As the level goes down, the number of bits available also decreases, so the distortion goes up.While this is true, distortion of any kind on –60-dB test signals for 16/44 digital is no higher than 0.15%. Furthermore, we now have high-resolution digital with 24-bit quantization. If musical peaks equal 24-bits, -60-dB must equal 14-bits. At 14-bits on a 24-Bit system, distortion of any kind will not exceed 0.015%
On the other hand, the only test that matters is listening. If you have a digital recorder of reasonably high quality and you copy an LP, I don’t think you’ll be able to tell the difference between the digital copy and the LP.
Best regards,
John Elison
Just realized there was one important typo...corrected in bold
First, though: remember that I am not anti-digital; I was simply responding to a massive over-simplification re the capabilities of 44.1/16. In one of the posts on this thread I did state that I thought something like 24-bit > 92kHz digital should be able to do everything vinyl can do....That said, I find it fascinating that so many people have reported better sound from CD copies of LP than from commercial CDs . One possibility is that the process of creating a commercial CD involves manipulation that creates the "CD signature", as opposed to the inherent AD-DA process itself.
I have tried a few experiments using my Meridian processor that digitizes all incoming signals for processing and then recreates analog for output. Matching levels as closely as possible, I find that the feed that has been through AD-DA conversion is very slightly drier and flatter than the original. Less sense of space and reverb. Obviously, since this was not double-blind testing it's not proof of anything at all......
So, back to the distortion question....
Isn't -60dB roughly 10 bits down? That leaves 6 bits, right? 64 possible levels....
I haven't tried looking at the distortion spectrum of a digital signal at this level, but I suspect it's pretty ugly, and composed of lots of high-order harmonics. (Unfortunately, my spectrum analyzer is in storage for another 6 months or so due to remodeling, so I can't try it right now..)
I wonder what the distortion spectrum of your AT OC-9 would look like at an equivalent level? It's quite possible it's THD is WAY lower than 0.15%, and dominated by low order harmonics.
At these levels, my money is on vinyl for lower distortion. The real question is how musically relevant this is....
Interesting discussion!
Peter
"One possibility is that the process of creating a commercial CD involves manipulation that creates the "CD signature", "Actually it is the other way around: the process of creating a commercial LP involves manipulation that creates the "LP signature", whereas the CD is / can be a closer copy of the 2-track pre-master.
Of course, nobody said that the LP and its limitations doesn't lead to a style of mastering that ultimately better suits the majority of domestic replay conditions (system, room, allowable levels).
Hi Peter,I have an interesting comparison for you to look at. Below are two spectrums, one from the OC0ML/II playing the lowest level 1000-Hz sine wave I could find on a test record, compared to a –60-dB signal from a Denon test CD. The interesting thing is that they are directly comparable because I have chosen a zero-dB reference for vinyl at the +18-dB level of the torture track on the Hi-Fi News test record. There are very few records that exceed that level, so I think it represents a good full-scale reference for vinyl. The nice thing about this level is that it falls exactly at –15-dB on the spectrum just like zero-dB full-scale for digital. Therefore, if you accept this level as full-scale for vinyl, you can compare the two graphs directly.
One interesting thing to note is the excessive noise floor for vinyl that rises in the low frequencies due to RIAA playback equalization and arm/cartridge resonance. There might even be some turntable rumble involved, too, although I hope not. I have serious doubts that you would be able to hear anything below this noise because the spectrum analyzer cannot even identify anything.
Another thing to note is that although the harmonic distortion is lower on vinyl for the –35-dB sine wave compared to that for the digital –60-dB sine wave, the actual level of harmonics in the digital graph are lower than those in the vinyl graph.
This post is made possible by the generous support of people like you and our sponsors:
Top of Page ]
[ Contact Us ]
[ Support/Wish List ]
[ Copyright © 2025, Audio Asylum, all rights reserved ]
