Cd artifacts

Lazarus Short

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#2
Having seen graphs of digital sampling points superimposed on the DAC'd analog waveforms, I could see that the bass notes got good definition, with lots of data points to define the wave. Treble notes, on the other hand, had much fewer data sampling points to define the wave that was to come from the DAC. To me, it meant good bass, so-so (but mostly OK) midrange and much-less-than-perfect high frequencies.

I have also heard CD's sound very, very good...and very, very bad - as bad as bootleg cassette tapes. So there's a LOT that can happen to the "perfect medium forever."
 

J!m

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#4
Well not specific to digital but it is VERY common to gate cymbals in the recording studio (to reduce bleed). If a particular passage fades to very quiet and they haven't adjusted the threshold, it can "clip" at low level.

The same recording in LP could sound much smoother as the sound fades into the noise floor, so it would not be as noticeable.

I would expect the master tapes, and good quality open reel tapes (commercially recorded), to show similar artifacts to the CD, because the noise floor is lower than LPs are able to provide.

Now, many DACs have a very "grainy" sound that many people have been trying to overcome including the used of distortion-laden vacuum tubes to smear the grain.
 

Makymak

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#5
I guess that at high frequencies there is a sort of dithering (Wikipedia). How I perceive this "dithering" is that at high frequencies, the sample rate isn't enough to "drow" the waveform with accuracy. This leads to zones where the amplitude is as the original and zones where the amplitude is reduced. If the waveform is a pure sinus, these zones are periodically. Well, music is not a sinus waveform but it consists of such. Some sounds that have more clear waveforms are more prone to such behavior. In addition, as going higher in frequency, this is getting more obvious.

Jim, I understand what you mean. The fact is that I can hear that at quite high volume, well above the noise floor of each medium. For example, at "Grease" soundtrack, the song "Born to hand jive" has a solo of percussions. On the LP the cymbals sound smooth. On the CD don't.
 

J!m

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#6
What you say is true in the digital domain.

BUT, all DACs then convert to analogue. (before this, pretty much all DACs are equal- there's only so much info to extract). How the "wave form" is processed and "smoothed" in/after the chip(s) is where the "sound" of a DAC happens.
 

J!m

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#8
It can't. But the analogue section can't reproduce the digital wave form exactly as presented- it has to "connect the dots" because it does not have the instantaneous response of the digital on/off of the digital "wave" (step) form. This ends up being an advantage to "smooth" the edges. Perhaps why tubes "sound good" in a DAC- even lower slew rate than ICs. I don't personally care for tubes here.
 

Makymak

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#10
I totally agree, Jim. A sinus wave that has been like a saw in it's digital form, it will be restored as a saw with smoothed teeth by the analog part of the DAC. But it never will be as close to the original.

I don't know, though, if there are existing some more sophisticated DACs with implemented algorithms that try to guess the original waveform and restore it with a more accuracy. If such DACs exist, they should be quite rare and expensive.
 
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#13
Go SACD. The sample rate is high enough to render high frequencies properly.
The combination of low sample rate and the 20Khz brick wall filter add up to large amounts of undesirable phase distortion on red book CDs
Yes, SACD or high res files can get very close to vinyl or master tape. Redbook can really suck at times, although I have some that are very good. Go figure.
 

VSAT88

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#14
All I know is this. On my digital recording often I notice crash cymbals sound like real crap. When I start to notice it I can un notice it and then I gotta turn that album off and go for something else to listen at. It sucks because some of my favorite music sounds that way.
 

J!m

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#15
Poor conversion is most noticeable at the upper frequencies.

But I’ve been mastering in the Alesis Masterlink and those converters are held in high regard, because they don’t have that over crispy brittleness. All the tapes I’ve sent out go through that process, and I (and others) think they sound decent.
 
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