Stupid question

Audio Systems
1

Hi everyone, lowly Puccini + Clock owner here (but I still love it!!!)

I’d really like to ditch the disk. First, I am an environmentalist and hate the idea of supporting more plastic. Second, I love the elegance of bits, and accordingly, the cleanness of the Bartok and Rossini DACs.

Most, if not all, reviews, claim that the spinning disk still outperforms the all digital route, assuming the same equipment, e.g. (disk in Rossini player) versus (ethernet + Rossini DAC)

As an engineer, admittedly a poor one, this makes no sense to me. Spinning a disk, reading the disk, and feeding the bits to the DAC is a mechanical+digital path that should underperform a pathway that is solely digital.

What am I missing?

Thanks in advance for entertaining my basic question, and greeting from NYC.

2

Hi,

When people say the spinning disk outperforms the digital route, they talk about the vinyl disk.

Cheers

Ch.

3

You will find several reviews of e.g the Vivaldi stack where the reviewer says it is the first time that they have heard file replay compete with ( silver) disc replay . Like this one ( para.4):

https://www.hifiplus.com/articles/dcs-vivaldi-20-digital-playback-system/

There are just so many things that can go wrong with playing either source. It is not just a question of moving data from A to B. For example precisely when the data is moved and processed is a major issue . I recall the original white paper that dCS issued way back before the turn of the century where they point out that you need to process the correct sample . An incorrect sample includes one that otherwise would be correct but is at the wrong time. This is an issue that particularly affects digital sound as mistiming distorts the required waveform. Further ears do not have an equivalent to persistence of vision, the latter allowing text or other images to be built up gradually on a screen without our being aware of the process.

Computer based reply of digital music files may not be able to provide timing that is synchronised with the processing of the DAC i.e. it is isochronous rather than the preferred asynchronous.

This covers in brief only a single issue and at my dummy level. I am sure there are many others that result in a poor listening experience and which technical advances e.g. available from dCS equipment have largely resolved.

4

Thx Chris.

As I own the Puccini stack the question is about CDs versus pure digital transport.

5

Thanks for your response, and I appreciate the issues you bring up.

Maybe I can ask it this way:

What is it about reading bits from a high velocity spinning disk and feeding that to a DAC, that would be more stable/better than moving bits from a static USB, plugged directly into the Rossini, for example, that would make the former outperform?

(Intrinsically this makes no sense to me…)

6

If you are talking about a current generation dCS transport connected to a dCS DAC /network board with both receiving identical clock signals from a system clock then there may be little to distinguish what you hear from replaying the same file stored on silver disc or a file stored on a NAS. I say “same file” as there is no guarantee, for example, that the download of a title is the same as the nominally same CD. But even given the same clocking I am not saying that there would be NO difference as even, say, the NAS can make a difference . That is because there are issues outside of digital transmission that can impose themselves. Parasitic EMI and RFI come to mind. They have no impact on the data itself but can be fed through the system connectivity and circuitry to the analogue stage of DAC and thus affect what you hear. I guess that I should also mention cable performance and network switching but as I know that these are difficult and controversial areas so I will move on from both of them leaving a ?

Often at a detailed level comparisons of CD v. file replay are not strictly comparing like with like and a precise comparison where only the source medium is different can be difficult to arrange in practice. For instance, from your example the CD data is sent to the DAC by ,say, S/Pdif but the file data by USB. The two are not identical and each protocol will involve its own set of compromises .

This is all just scratching the surface.

7

Thanks again Pete, this is exactly what I am interested in. Let’s eliminate all variables. Same exact system, verified bit perfect match of CD and lossless, uncompressed AIFF file. I’m interested in thoughts on, precisely, if I should perceive sonic differences in the below:

(a) Rossini player spinning the disk;

(b) Rossini player reading the AIFF file from a USB stick, inserted in the back of the player;

My thought was that (b) is a less complex path and therefore should be inherently more stable/better…

Thanks again!

8

This moves the question to a specific replay chain and provides circumstances that I believe are different from those which probably resulted in the commonly held belief that disc replay sounds better then file replay.

Using two inputs on the same machine removes some of the obvious suspects for influencing the resultant sound negatively for such a comparison. From an intuitive viewpoint both CD and file on the USB drive should sound the same especially as both sets of data will be buffered by the Rossini before being sent for conversion.

One factor might affect this though is the question of error correction. CD has error correction baked in whereas isochronous USB appears not to for all categories of data transfer, at least from what I have read. However I am unable to say what the case is in your example as this would require more detailed knowledge of both the Rossini and the USB flash drive than I possess. I presume that USB 2 port on Rossini ( configured for flash drives) is asynchronous but I don’t actually know. I do know, however, that the USB inputs are not considered to provide the best sound compared to network connection for any dCS device that provides the latter. You may need one of the dCS engineers to explain exactly why.

9

@keiserrg I cannot answer your question about the merits of one specific configuration vs. another. i can only give you my general view.
If I look at the BER specs of USB, I doubt very much that bit errors (which would be corrected by the CD and not by the USB connection) would make any meaningful difference. See my post here. Moreover bit errors would not manifest themselves as constant changes in sound characteristics, but as clicks when the error occurs.
I suspect that any effect that is perceived is due to analogue effects that propagate over the physical cabling and electronics and then influence the analogue signal stages.
I believe the same thing holds true for audio optimized ethernet switches and their power supplies. I don’t believe they do anything to the bit sequence, but filter out analogue disturbances. I have a Melco S100 and a Paul Hynes SR4T on order
:grinning:
Having said all that there seems to be a consensus that current dCS gear sound best using the Ethernet input.

.

1 Like
10

Under the hood there are many other factors influencing CD play, and file play.

I find the following application note very interesting:

Extending the Performance of the CD Format

Fortunately, we have learned how to extract more performance from the CD format. Newer recordings use noise-shaped dither to reduce the 16-bit quantization noise to a level that is equivalent to that of a 20-bit format. Oversampling converters with specialized filters have improved the high-frequency performance in the region between 18 kHz and 22 kHz while reducing distortion at all frequencies. These oversampling converters can also accurately reconstruct the original analog waveform between samples.

These spectacular improvements have brought the theoretical performance of the 35 year old CD format very close to that of the new high-resolution formats. Old recordings benefit from the improvements in D/A converters and power amplifiers. Newer recordings add the the benefits of the noise shaping and improved A/D conversion used to produce the recordings.

From:

2 Likes
11

Wouldn’t that apply to a WAV file of the same recording as well?

12

If you read the article, you see it depends on if these 2 recordings are of the same date. It might very well be that the process of mastering, or of digital extraction, has been, or is being, corrected, compared to the original CD production.

13

@Ermos You are absolutely correct. Have you found any information about how widespread the issue of Intersample Overs is? The articles on the subject I have seen to date seem to point to few and singular cases which were probably corrected in subsequent editions.

1 Like
14

I do not know how well the music industry adheres to best practices and standardisation nowadays. But the inter-sample peaks do occur regularly on older CD productions.

The issue of inter-sample peaks is an inevitable by-product of the Loudness Wars and the lack of regulation and standardisation in the music industry. To a large extent, the problem of inter-sample peaks could be easily negated by an accepted peak level of -3dBFS, following the lead of other industries such as film and TV broadcast, where prescribed final signal levels and loudness standards are strictly adhered to. The music industry, though, has a distinctly more cavalier attitude, with loudness seeming to be all that counts, and that audio quality is often the least important point on the agenda. The irony, of course, is that peak levels aren’t the principal component of loudness, but instead formed by the averaged RMS levels.

As more engineers, musicians and listeners of music understand the phenomena of inter-sample peaks, though, it becomes increasingly easy to start making more informed choices about how our music sounds. Arguably, industry-driven initiatives such as ‘Mastered for iTunes’ illustrate that there’s a degree of reappraisal happening concerning issues such as loudness and data compression. In the future, therefore, there may well be a move towards less distortion and higher bit-rates, meaning that inter-sample peaks could become a thing of the past.

From:

2 Likes
15

For me i have found that all this has changed as i have upgraded certain bits in the chain.
I have a rossini player and clock.
I also have a melco N10 that has all my ripped CD’s stored on it, all ripped using the melco D100.
My streamer side, comes from the router, then 7m of catsnake 6 floating cable, into a Cisco switch, then it goes into the melco N10 using 0.75m catsnake 6 floating, and then from the N10 to the rossini using AQ diamond, 1 meter long.

Right now how my system is, the ripped CD’s from the N10, sound slightly better, more open and dynamic than the same CD playing in the rossini.
The same album streamed in CD quality, sounds to me just like the ripped CD.
So for me the player is the worst sounding, but this hasn’t been like this all the time.

I have run different melco’s, cables, switches into the rossini, and at the beginning i preferred the CD player slightly over the others, at the time i was using a melco N100, no switch and very cheap network cables, the power supply on the melco, put loads of noise into the mains, and imhad to remove it from my dedicated mains as it was so bad, i have also had the melco N1ZS/20, this was a massive improvement and with the ethernet cables i mentioned above, then i found that the ripped CD’s sounded as good, but my streamer side had taken the lead just, at this point i was thinking about selling my melco, as i was not using it to play any ripped tracks, and just streaming them from qobuz.

After having a long chat with my deal about my melco, he suggested that i tried the new N10, as its basically the same as what i had, but in 2 boxes, bit more importantly a different sound, more forward and alive, rather than the smooth delivery from the N1ZS/2.
So i did, and yes it made a difference that i was very happy with, so thats been my journey, but what i have found is that with it all, it all needs attention to get the best from it, this streaming is not as easy as say a CD player that you just make sure its level, on a good stand and plug it in, to get the best from streaming takes more time i found, little things can make a nice improvement, but it all depends on your own network, how much time and effort you want to put into it all.
I still stream most of the time, as i listen to stuff i haven’t got ripped, but if i want that extra bit of quality, and i have it stored on my melco, then this is my go to.

Hopefully this might have been of interest, if not then sorry for wasting your time.
Cheers dunc

1 Like
16

I think this gets to the heart of the matter Pete. I will try to get an answer from DCS on this and if I do, reply to the chain.

Thanks again for sharing your thoughts and insights!

17

dCS USB Inputs:

  • USB 2.0 interface on a B-type connector operating in Asynchronous mode, will accept up to 24 bit PCM at up to 384kS/s plus DSD/64 & DSD/128 in DoP format. Operates in Class 1 or 2 mode.

  • USB-on-the-go interface on type A connector operating in Asynchronous mode, streams digital music from a flash drive at up to 24 bit 384kS/s plus DSD/128.

[kS/s = kiloSamples per second]

From:

https://www.dcsltd.co.uk/products/rossini-dac/specification

1 Like
18

Thank you @Ermos!

19

Some more interesting reading on intersample overs (further down the page):

20

When you talk about cd and you compare it with a ripper one, you may not forget that for cd many supports exist, like sacd, shm, bluspec… and those bring a lot of diffences…