Analog sound: Real or myth?

[davetroy]

I suspect I'm going to take some abuse for asking these questions, but here goes. Hey, if I asked them at Audiogon, I'd probably get banned.

I often see people talking about "analog sound" and how certain CD players are supposedly better at producing "analog sound." Here are my questions:

1. Has anybody ever done blind listening tests in which a CD player was compared to, for instance, a turntable? If so, what were the results?
2. What the heck is analog sound? I know it's the sound of vinyl records played on a turntable, but what is the supposed audible difference between analog sound and the sound from a CD player?
3. Is it possible for a CD player to produce this so-called analog sound?

If there's another thread on this topic that I've missed, please direct me to it. I haven't been able to find one. I'm asking these questions because of all the audio things I'm skeptical about (cables, etc.), getting better sound from a supposedly high-end CD player is the one I'm most skeptical about. And because, for the most part, I missed the vinyl age.

Thanks,
Dave

 

[outsider]

In order for you to hear the sound, it has to be analog. That is why a CD player has a Digital to Analog Converter (DAC; D/A Converter).
The quality of the DAC, along with the quality of the internal components of a CD player contribute to the quality of the output signal which effects the quality of the sound coming out of your speakers.

Can anyone tell the difference between different CD players when both are A/B tested with the same preamp, amp, cables, and speakers? Probably a few can, but the average person would have a hard time.

 

[mtrycrafts]

I suspect I'm going to take some abuse for asking these questions, but here goes. Hey, if I asked them at Audiogon, I'd probably get banned.

Well, you came to the right place then. No banning, no abuse. Just some discussions

I often see people talking about "analog sound" and how certain CD players are supposedly better at producing "analog sound."

Analog sound is kind of subjective, isn't it?


[v]1. Has anybody ever done blind listening tests in which a CD player was compared to, for instance, a turntable? [/b]


Why would anyone compare those two? Of course they sound different. One should ask, which is more accurate to the signal at the mic cable output? One guess only


2. What the heck is analog sound? I know it's the sound of vinyl records played on a turntable, but what is the supposed audible difference between analog sound and the sound from a CD player?

Vinyl has tremendous limitations compared to the CD capability, period, end of story. After that, some just make excuses. Or, just expressing a preference. Hard to discuss a preference in technical terms.



3. Is it possible for a CD player to produce this so-called analog sound?

Certainly. Record a vinyl to a CD and you have it. It will sound like that vinyl.


[v] I'm asking these questions because of all the audio things I'm skeptical about (cables, etc.), getting better sound from a supposedly high-end CD player is the one I'm most skeptical about. [/b]


As you should be.
One can design a CD player to be euphonic. Or, one that is accurate. Price does not dictate accuracy, by the way
To get better sound, concentrate on your speaker's quality, your room acoustics and the quality of your CD. Much of modern music is compressed to the hilt, and sounds terrible. That is not the fault of the medium but what the market dictates
These 3 items makes the most audible differences, not the rest of the chain combined.


And because, for the most part, I missed the vinyl age.
Thanks,
Dave


Then, you have less to worry about. You don't have a nostalgia to feed. But, you do need to concentrate on the 3 issues above.

 

[tbewick]

I haven't been able to find one. I'm asking these questions because of all the audio things I'm skeptical about (cables, etc.), getting better sound from a supposedly high-end CD player is the one I'm most skeptical about. And because, for the most part, I missed the vinyl age.

Thanks,
Dave

Strangely, I think it's possible that you could get better sound on lower quality playback material on a higher-end player, due to their DAC designs. This may be down to digital clipping:

'For an FIR filter the very maximum output value, or overshoot, will occur with an input signal that causes the magnitude of all the coefficients to be added. This input signal would consist of positive and negative full-scale values that all have the same sign (or all have the opposite sign) as the coefficient with which they are aligned. This pattern is very unlikely to exist in a real signal but represents an upper bound to the amount of overshoot that could occur. This value is shown for each of the filters in figure 1 to 4 and can be seen to vary between 2.9 and 5.7dB.

Clipping of DAC interpolation filters can often be observed when presenting them with a square wave peaking at close to full scale. (This may look clean but it can be shown to be clipping by reducing the level slightly and a clipped ringing overshoot will be observed on the filter output.) This clipping represents a sharp, or high order, non-linearity that should be avoided.'

- Julian Dunn - `The benefits of 96 kHz sampling rate formats for those who cannot hear above 20 kHz' Preprint 4734, presented at the 104th AES Convention, Amsterdam, May 1998. http://www.nanophon.com/audio/antialia.pdf

As it says, this shouldn't occur in normal signals, but as mtrycrafts says, a lot of pop music is compressed very close to full-scale nowadays. I don't know of any proper tests that have examined how audible clipping typically is with such material. Personally I like to renormalize aggressively mastered CD tracks to a lower volume in order to give the converter's analog filters some headroom.

I'd say that top-end CD players will offer higher quality performance in objective terms, but most half-decent players should perform exceedingly well.

There was meant to be some issues with early digital recordings because dither was not used properly, meaning that low volume signals became distorted. Criticism here then, of early digital systems, may be valid. Some people do like the vinyl sound because they do often sound warmer, but this is probably mostly due to vinyls having less top-end treble than CD's.

 

[davetroy]

Certainly. Record a vinyl to a CD and you have it. It will sound like that vinyl.

From my experience, that seems to be a bad thing. In the classical CDs I have that were originally released on vinyl, it seems as if the high ends are cut off, especially with voices and horns. I guess shrilly might be the word.

 

[MDS]

How was the vinyl recorded to a CD? If you do it properly and use the appropriate pre-amp with the built-in RIAA curve then the recording quality will only be limited by the quality of the analog to digital conversion (which is pretty good even if you use your computer's sound card to do it).

In other words, it should sound pretty much the same as the record as mtrycrafts said.

 

[mtrycrafts]

Are these CDs your copies of vinyl or from music companies out there?
How old are they if commercial CDs? If, they are way back when CDs came on the market, there was growing pain by the recording engineers. Cds have flat response to 20kHz and to full scale.

 

[yettitheman]

Analog... ah, makes me all warm and fuzzy inside.

Either way, whether it be a digital or analog connection, a DAC is needed so the amp can spit out tunes through the speakers. The difference being where amplification and the conversion takes place. Some CD players do it better than the DAC's in a reciever, and sometimes the CD player's DAC's blow. (gross exaggeration, but you get what I mean)

 

[Nick250]

The quality of the media is far and away the biggest variable in my experience. Some Cd's have great sound, though most I listened to do not. In particular, the lack of dynamic range bothers me the most.

Nick

 

[jonnythan]

I think that when people talk about "analog sound" they're most often referring to sound that was never digitized or passed through solid state electronics. Recorded to an analog medium, mixed in an analog environment, pressed to an analog record, and amplified by an analog, non solid-state devices tube amps).

Or, at least, sound reproduced from an analog medium (a record) as opposed to a digital one (cd/mp3/SACD/etc)

 

[Seth=L]

When speaking about audio quality you almost always should be looking at the source of the recording and not so much the medium used. Most music production companies record the master tracks digitally now days. Very few still record analog. Some times if you buy a new vinyl it may have been copied from a digital master, pretty much making it a moot point or even make it sound worse than if it had been copied to CD.

Data compression and dynamic compression are common problems associated with CDs and LPs that are derived from a digital master. Strict analog recordings for some reason sound more dynamic and real because perhaps it is more difficult to manipulate an analog recording in the digital domain. The calculations required would probably be more difficult at least they used to be.

The point is that it is much simpler and more cost effective to record digital and production companies will do exactly what saves them money. With all the people listening to MP3s and illegally copied music you can expect them to cut corners everywhere. And most importantly, they are not selling to audiophiles, they are selling to those that think the iPod is a high quality audio device. Most people don't notice that their newest CDs sound bad because they have crap for audio components and/or they don't care as much as the audiophiles do.

The only thing that I don't understand is why they see that it is fit to compress the dynamics of an audio track. Are they doing it to limit the feasible damage to our audio components? If that is why they are only trying to protect themselves from possibly being sued because the dynamics damaged something in a sound system. I wish I knew why they did it, I would think it would raise costs to compress dynamics. What do I know though, right?

 

[davetroy]

When I said vinyl recorded to digital, I meant analog recorded to digital. The recordings are mid-1950s opera recordings, and although the sound on the CDs are generally very nice (Testament label; really nice stuff), the only time things go sour is when the horns go high or the voices get high. Then, it seems as if the sound hits a ceiling and gets very bright. It's not a problem with my system; it's probably a problem with the analog to digital recording, from what I can tell.

That's why I say that from that experience, analog or vinyl sound is not what I want. And I suspect that the warmth and lack of electronic sound I'm looking for (in classical and opera recordings) will only come with improved speakers because even with very good recordings, there's just that touch of electric. I don't know any other way to put it.

 

[Seth=L]

You must realize that CD has it limits. Have you tried SACD or DVD-Audio in high resolution 2 channel?

Vinyl, for the sake of things, has a wider frequency range than CDs I believe. What speakers do you have? What are your other system components? Do you have acoustic treatments or lack treatments that could possibly be detrimental to the upper-end?

 

[tbewick]

When I said vinyl recorded to digital, I meant analog recorded to digital. The recordings are mid-1950s opera recordings, and although the sound on the CDs are generally very nice (Testament label; really nice stuff), the only time things go sour is when the horns go high or the voices get high. Then, it seems as if the sound hits a ceiling and gets very bright. It's not a problem with my system; it's probably a problem with the analog to digital recording, from what I can tell.

One of the things that was done on some digital versions of old 78 recordings was CEDAR (Computer Enhanced Digital Audio Recording). In some cases this improved sound quality, but in others it could lend a shrill tone to some instruments. I've read that the Nimbus record label had a somewhat surprising alternative technique for removing hiss on early recordings. What they did was to replay the record on an old Gramophone with a huge acoustical horn in a concert hall and re-record it digitally. Using a thorn needle helped to lower hiss and subjectively the technique helped to curb 'peakiness' in the final recording.

Data compression and dynamic compression are common problems associated with CDs and LPs that are derived from a digital master. Strict analog recordings for some reason sound more dynamic and real because perhaps it is more difficult to manipulate an analog recording in the digital domain. The calculations required would probably be more difficult at least they used to be

I used to have this feeling, but after trying to extend my CD library based on recommended digital recordings, my opinion has changed entirely. You only have to listen to some high-quality digital recordings, e.g. Telarc releases, to realise what sound quality is available from the CD format.

 

[davetroy]

If only one could consistently rely on a label for the combination of quality performers/quality recording. For classical, I've found that Reference is good. Telarc is good. Testament is mostly good, considering they're releasing old recordings. But companies like DG, Phillips, etc., are very hit or miss.

 

[Seth=L]

Not all CDs that were copied from a digital master are bad, that isn't what I meant, sorry for any missunderstanding.

 

[mtrycrafts]

You must realize that CD has it limits.

What would those limitations be?

Have you tried SACD or DVD-Audio in high resolution 2 channel?

I didn't know you can hear ultrasonic sound


Vinyl, for the sake of things, has a wider frequency range than CDs I believe.

If you can capture it on vinyl without burning out the cutters, or able to record the volume level.
The CD will record everything you can hear to 20kHz. Can you hear 20kHz? If not, why worry?

 

[Seth=L]

What would those limitations be?

I didn't know you can hear ultrasonic sound

If you can capture it on vinyl without burning out the cutters, or able to record the volume level.
The CD will record everything you can hear to 20kHz. Can you hear 20kHz? If not, why worry?

I was making suggestions.

I can hear differences between DVD-audio and CDs in two channel. Is it because of ultrasonics?, no. DVD-Audio is a medium with larger storage allowing for less compression (that being the downfall of CDs, compression). I also think that with so few DVD-Audio and SACD music that they probably take more time and consideration when making them, though it probably wouldn't be much.

Perhaps the statement about LP was not relevant.

 

[MDS]

DVD-Audio is a medium with larger storage allowing for less compression (that being the downfall of CDs, compression).

DVD-A supports higher bitrates and longer word lengths than CD but that is not related to compression. You can compress the crap out of 24/192 just as easily as doing the same to 16/44.1. You just have more samples to muck with in a high resolution format.

 

[jonnythan]

that being the downfall of CDs, compression

A slower sampling frequency is *not* compression.