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Pasanda

Digital music

47 posts in this topic

2 hours ago, Pasanda said:

Connected the CD player to streamer using digital phono connection, again to exploit the superior DAC of the streamer.

Interesting choice if odd reasoning, since the source is already digital.  Or am I missing something?

Edited by Elovia

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15 minutes ago, Elovia said:

Interesting choice if odd reasoning, since the source is already digital.  Or am I missing something?

If you use the digital out on the CD player it bypass the CD players own DAC, and just transfers the data to the streamer. The streamer has a (supposedly) far superior DAC. 

That's the theory anyway.

From reading around the topic, the quality of conversion from digital to analogue is one of the most important aspect to transporting music from digital source to speakers, in the highest quality manner.

Or am i misunderstanding the question?

Edited by Pasanda

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30 minutes ago, Pasanda said:

Exactly like this:

 

sound-waves-moving-graphic-illustration_

smart arse.

...there's way too much information to decode the sound. You get used to it, though. Your brain does the translating. I don't even see the waves. All I see is blonde, brunette, redhead.

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1 hour ago, Pasanda said:

If you use the digital out on the CD player it bypass the CD players own DAC, and just transfers the data to the streamer. The streamer has a (supposedly) far superior DAC. 

That's the theory anyway.

From reading around the topic, the quality of conversion from digital to analogue is one of the most important aspect to transporting music from digital source to speakers, in the highest quality manner.

Or am i misunderstanding the question?

I think so.  My knowledge on the subject is far from expert.  The source data on the disk is digital, and when sampled the waveform will have vertical and horizontal components (at the peaks).  The resolution of which are determined by the sampling rate of the original analog-digital conversion that put the data on the disk.  At best, a re-translation of the digital signal back to analog will mimic the source (assuming the reading conversion sampling rate is greater than that of the source), and the resulting output wave form will not have curve-linear connections between positive and negative peaks as would with an analog source (although it may be closely approximated).

In other words, unless your CD player DAC's sampling rate is less than the source on the disk, and your new DAC sampling rate is greater than that of the source disc (naturally assuming it is greater than the DAC on the player), you'll not see any benefit.

tl;dr ... garbage in -> garbage out

 

Edited by Elovia

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On 7-9-2017 at 2:19 AM, Elovia said:

Given the same analog source material, digital music will never be as "good" as the original analog (note: "good" is a relative term), due to the lossy nature of the conversion from analog to digital.  To be fair, at very high sampling rates, digital music can approach the quality of analog, but the losses are still there.  Now the question is, "can those losses be discerned?"  See my first point.

 

 

1 hour ago, Elovia said:

The source data on the disk is digital, and when sampled the waveform will have vertical and horizontal components (at the peaks).  The resolution of which are determined by the sampling rate of the original analog-digital conversion that put the data on the disk.  At best, a re-translation of the digital signal back to analog will mimic the source (assuming the reading conversion sampling rate is greater than that of the source), and the resulting output wave form will not have curve-linear connections between positive and negative peaks as would with an analog source (although it may be closely approximated).

 

I feel compelled to quote a few things from the web.

Quote

Myth: Vinyl is better than digital because the analog signal on the vinyl tracks the analog signal exactly, while digital is quantized into steps

Frequency resolution
The Nyquist-Shannon sampling theory states that continuous-time (analog) signals and their corresponding discrete-time (digital) signals are mathematically equivalent representations of any bandwidth-limited signal, provided the sample rate is higher than 2X the bandwidth. All relevant advantages and disadvantages result from implementation details rather than analog versus digital signal representation method. Perhaps the most common method of storing a digital signal is with pulse code modulation (PCM). PCM is used on CDs and DVD-A.
PCM is sometimes characterized as producing a jagged, "stair-step" waveform. This is only partially correct; analog-to-digital conversion (ADC) does indeed use a sample-and-hold circuit to measure an approximate, average amplitude across the duration of the sample, and digital-to-analog conversion (DAC) does the same kind of thing, generating a rectangular-ish waveform, but this output is always then subjected to additional filtering to smooth it out. Effectively, the ADC output sample values are interpreted as a series of points intersected by the waveform; the DAC output is a smooth curve, not a stair-step at all. Additionally, modern ADC and DAC chips are engineered to reduce below the threshold of audibility, if not completely eliminate, any other sources of noise in this conversion process, resulting in an extremely high correlation between the input and output signals. (Perhaps a better explanation: xiph.org's "Digital Show & Tell" video)
A related myth is that components of the signal near the Nyquist frequency must be square waves on CD (or digital media), and that vinyl (or any analog media) preserves pure sine waves. The premise is false. A square wave, or any wave that's not a perfect sine wave, is the sum of multiple pure tones (sine waves), by definition. So if you have a pure 22.05 kHz signal on CD (i.e., sample values +n, -n, repeatedly), the DAC may first construct a square wave, but the reconstruction filter then filters out everything above the Nyquist frequency, leaving behind a sine wave. The principle is the same even in complex waveforms. The end result is that the uppermost frequency components on CD are no closer to being square waves than they are on vinyl.

<snip>

Vinyl is often sourced from digital anyway
Since the mid-1970s, vinyl mastering houses began using digital delay lines instead of analog delays on the signal going to the lathe that cuts the spiral groove. So even in the increasingly unlikely event that 100% of the recording, mixing and mastering was done entirely using analog gear and media, the end of the vinyl mastering process may well have involved a conversion to digital and back.

 

Quote

Certainly the act of putting a record on a turntable and having to change it every 20 minutes makes the listener feel more involved with the music. It's different from sitting back and letting your CD changer do its thing. However, by any measurable criterion, CDs are superior to LPs. And so are MP3 and AAC files with bit rates above 300k, which in most cases are indistinguishable from CDs. Here are the reasons why:

<snip>

Continuous vs. "chopped up." Some people believe that because digital audio "chops up" the signal into discrete numbers, it cannot carry all of the information that an analog signal does. But before the digital signal reaches our ears, it is reconstituted into a continuous analog wave. The process does filter out sounds above 20 kHz, which is the highest frequency the most acute human ears can hear. However, no phono cartridge, amplifier or speakers can reproduce those frequencies anyway. So really, nothing is taken out that affects the sound.

<snip>

 

Further reading:

http://wiki.hydrogenaud.io/index.php?title=Myths_(Vinyl)

https://phys.org/news/2016-07-music-vinyl-cds.html

 

 

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40 minutes ago, Elovia said:

Nice red herring and beside the point.  But thanks for chiming in. (see wut I did there?)

Quite happy to state i have no idea what either of you were talking about. But i thonk i got that it wouldn't be any worse...?

If nothing else, the analogue phone outs on the cd player were quite heavily corroded. So i was happy to avoid them.

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8 minutes ago, Pasanda said:

Quite happy to state i have no idea what either of you were talking about. But i thonk i got that it wouldn't be any worse...?

If nothing else, the analogue phone outs on the cd player were quite heavily corroded. So i was happy to avoid them.

Here's an analogy to help with my point ...

Playing a scratched or warped record on a really high end record player won't improve the sound output; you'll still hear all of the defects in their crisp glory.  Likewise on a CD player, older CDs had low sample rates when they were originally pressed (hence, the proliferation of remasters).  Your player was probably good enough back in the day to play CDs from those times, and a modern CD player (or even really good DAC) won't clean up the defects from the old disc.  Newer CDs on the other hand, and newer digital music (depending on format), are likely to be better quality sources and you may see a benefit by not playing them through your old CD player.

 

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Ok. That makes sense. Just a few unknowns like.

Was the CD Players DAC good enough for all my old CD'S?

My son has some new CD's for the cars. Perhaps they'll be better?

Coincidentally someone on av forums made a very similar point about my speaker matching to my system. Saying that much better speakers won't give me better audio; they'll just show up flaws in the rest of the set up more. So better quality = better transparency. Not better audio.

I can understand the point but I'm not sure i buy it. I'd be fairly sure that better speakers also make more of the signals they get sent, in terms of the range of frequency response and quality of tonal reproduction. 

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19 hours ago, Elovia said:

Nice red herring

That assumes intent. It may be besides the point. I thought you meant music from analogue carriers (like LP's) is always better than music from digital carriers (like CD's), because the wave gets chopped up.

800px-Pcm.gif.040fd32d3b2af3399b26562f19fd410b.gif 

If that's not what you meant, then I am also in the dark about your precise point, and will accept it is over my head too.

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30 minutes ago, Wolphard said:

That assumes intent. It may be besides the point. I thought you meant music from analogue carriers (like LP's) is always better than music from digital carriers (like CD's), because the wave gets chopped up.

800px-Pcm.gif.040fd32d3b2af3399b26562f19fd410b.gif 

If that's not what you meant, then I am also in the dark about your precise point, and will accept it is over my head too.

Not quite, no, but close.  What I meant was ... (I'm going to use some numbers for the sake of discussion, not that they're real) ... if the source was sampled and printed on the disc at 100 Hz (100 times per second), and was read at 1000 Hz is not the same as source sampled at 500 Hz and read at 500 Hz.   The flaws in the original become more evident because, as you pointed out, the filtering algorithms break down with successive sample points at the same amplitude.  Or in the reverse case where the original was sampled at 1000 Hz and read at 100 Hz, information is simply lost because it was not read.  To be as concise as I can, I meant to address the differential sampling rates between source and reader.  Couple that with the fact that older CDs and CD players used compression/decompression algorithms to get the data on the disc.  Today, optical storage media technology is much better and has higher density.  Modern digital music has much larger file sizes (i.e., no compression and higher sample rates) because they're not constrained by media size.  To state the obvious, the listening quality of an MP3 is not the same as a FLAC.

Although to be fair, and this goes back to one of my much earlier points, as we reach older ages, we lose the ability to discern the difference.

What I'm discussing from my perspective applies not just to music but also to any kind of instrumentation where time-dependent analog data is measured and recorded.  I certainly didn't intend for this discussion to blow up.  I merely thought it curious how Pasanda intended to connect his equipment and why.  Not that it is wrong, but I thought i'd ask for my clarification and understanding in case I was missing something. 

 

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Personally, i think the whole digital vs analogue debate, where analogue fanbois talk about warmth etc. is all snake oil. Not that i don't believe some analogue setups aren't warmer than digital. I also believe that some digital setups are warmer than analogue.

While we're at it, i've seen that stepped curve vs liner curve argument before. Similarly, that's all bullshit. Just watch the completely digital recent episodes of Blue Planet 2 and tell me they're not better than the best of analogue. Step it as much as you like, it's all down to resolution, and humans simply cannot tell whether some of the higher def recordings are digital or not.

The irony of that image is that both the digital lines and the analogue lines are digital. The fact that a high resolution line cannot be discerned as digital only serves to illustrate the point.

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2 hours ago, Jazz said:

I'm tone deaf and have been threatened with torture and death for my singing, that should establish my position on the matter.

Apparently, tone-deafness is not necessarily any reflection on ones appreciation for music.

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I can't accept that. I bought a rechargeable bluetooth speaker with radio built in for 82p, including postage, from China a few weeks back. It sounds awful and i defy you not to hear a remarkable difference and appreciation in quality between them.

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37 minutes ago, Pasanda said:

I can't accept that. I bought a rechargeable bluetooth speaker with radio built in for 82p, including postage, from China a few weeks back. It sounds awful and i defy you not to hear a remarkable difference and appreciation in quality between them.

Power yes.  DvA?  That one is tougher.

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