Denon DCD-SA1 (CD/SACD Player)

[NTTY]

Just for the record, I think the following graph illustrates the kind of result one would expect by the use of such a test signal. It is an FFT obtained with an Audio Precision of the output of a player when reproducing a very low 16 bits/44.1 ksps PCM signal with noise-shaped dither engraved on a test CD:View attachment 392291

This graph was published in the Italian magazine AudioReview, where it happened that such measurements are publised from time to time: https://www.audioreview.it/prove/storiche/mcintosh-mcd301.html

Thanks for the reference and link.

There's another measurement published, this one (39kHz & 42kHz) with a view in linear frequency scale, up to 50kHz:

I don't have that double test-tone on the Denon SACD, but there are single 15kHz & 30kHz test tones overlayed (so it's not intermodulation distorsion test here), with the same representation, it shows:

But I think it's not representative, because if I extend the view to 96kHz:

There we see the (shaped) noise but also distortion as high as -60dB.

Would you know what test SACD disc they use?

Cheers

--------
Flo

 

[Scytales]

I must point out that I am no specialist. I have just researched the technical literature about the issue I tackled out of curiosity.

Among this technical papers, there are one by Reefman and Nuijten, from Philips, which was presented at the very same 2001 AES convention where Lipshitz and Vanderkooy presented their infamous paper that AnalogSteph obviously referred to in his above message.

This "match" was part of the fun of the format war between the DVD-A team and the SA-CD team.

In this paper, Reefman and Nuijten acknowledged the fact that every time a multi-bit signal is re-quantise to 1 bit, there are a noise build-up in the system. They illustrated the issue with gain adjustment processing stage: as the input of a re-quantising delta-sigma modulator must remain under its absolute maximum to avoid overloading the system, adding a huge amount of gain increases the level of the input signal (especially the shaped out of band noise component of the signal) to much for not overloading the following input. For that reason, they suggested the obvious: keep the signal multi-bit between the different processing stages (hence the "DSD-Wide" intermediate format between processing blocks) until the very last stage, just before exporting your mix for authoring in SA-CD. They also suggested to begin with a 4-bits delta-sigma or a higher oversampled (they suggested 256 FS) 1-bit delta-sigma recording.

By the way, the first pro-audio A/D converter from Sony for SA-CD production, the AD-1800RS (from the1999-2000 Sony pro-audio catalogue) was able do either 64 FS or 128 FS DSD output. To avoid noise build-up between processing stages, low-pass filtering is also apply before re-quantisation to 8-bits wide or 1 bit DSD, to tame the noise. As I understand, this intermediate filter stages during production is one of the reason that the final DSD release format is specified to have a signal bandwidth of 100 kHz only (albeit with a progressively lower signal-to-noise ratio from the upper of the audio frequency range to higher frequencies contrary to PCM, where the signal to noise ratio is constant).

Reefman and Nuijten have also evaluated the magnitude of the noise build-up issue during signal processing and they suggested that with up to 10 passes of re-quantisation, the accumulated low-pass filtering in all the re-quantisation stages have no significant effect on the specifications of the DSD signal. Nevertheless, they said that, at the time, the design goal of any processing on sigma-delta signal was to limit the number of re-quantisation steps along the production workflow.

They also said something Black Elk insisted upon frequently : the plan has always been that DSD64 would be the releasing format to the consumer and that higher rate or multi-bit delta-sigma modulation would eventually be used throughout the production chain, just as a PCM production chain uses higher specified PCM signals or an analogue production chain uses higher specified electronics to give room for the various signal manipulation necessary to create musical contents. The engineers of Sony Oxford made the same point.

In their paper, Reefman and Nuijten also wrote something which perhaps will answers haskil's interrogation about why the engineers at Sony and Philips have taken the sigma-delta route as a format.

They said that, to their knowledge, experimental evidences of their time (2001) suggested that if (and it is a big if, may I ad) ultrasonic frequencies above 20 kHz might be audible, it is only in the case where those ultrasonic frequencies are correlated with the signal in the 0-20 kHz frequency band. As the noise-shaped ultrasonic content of DSD is un-correlated to the signal, they saw it as audibly innocuous if perceptible at all. Then, it is possible, they said, to take advantage of the extended bandwidth of sigma-delta signal to apply very slow low-pass filtering at the reconstruction (D/A) stage, which keeps the time domain response very accurate.

 

[Scytales]

Thanks for the reference and link.

There's another measurement published, this one (39kHz & 42kHz) with a view in linear frequency scale, up to 50kHz:


Would you know what test SACD disc they use?

Most probably this one : https://www.audiosciencereview.com/...p503e-universal-player-2005.10016/post-272016

It contains frequency sweep to assess frequency response, single 1 kHz tone from 0 dB SA-CD to -160 dB SA-CD, 19+20, 39+42 and 83+85kHz twin tones, ...etc.

 

[NTTY]

For that reason, they suggested the obvious: keep the signal multi-bit between the different processing stages (hence the "DSD-Wide" intermediate format between processing blocks) until the very last stage, just before exporting your mix for authoring in SA-CD.

It makes sense indeed.

They also suggested to begin with a 4-bits delta-sigma or a higher oversampled (they suggest 256 FS) 1-bit delta-sigma recording.

Same here, go much higher resolution is kind of easy way to deal with the issue, providing storage et processing of data are not a problem.

They also said something Black Elk insisted upon frequently : the plan has always been that DSD64 would be the releasing format to the consumer and that higher rate or multi-bit delta-sigma modulation would eventually be used through the production chain, just as a PCM production chain uses higher specified PCM signals or an analogue production chain uses higher specified electronics to give room for the various signal manipulation necessary to create musical contents. The engineers of Sony Oxford made the same point.

Yeah, studios obviously need higher resolution to process tracks and mix them, to prevent audible negative effects.

In their paper, Reefman and Nuijten also wrote something which perhaps will answers haskil's interrogation about why the engineers at Sony and Philips have taken the sigma-delta route as a format.

They said that, to their knowledge, experimental evidences of their time (2001) suggested that if (and it is a big if, may I ad) ultrasonic frequencies above 20 kHz might be audible, it is only in the case where those ultrasonic frequencies are correlated with the signal in the 0-20 kHz frequency band. As the noise-shaped ultrasonic content of DSD is un-correlated to the signal, they saw it as audibly innocuous if perceptible at all. Then, it is possible, they said, to take advantage of the extended bandwidth of sigma-delta signal to apply very slow low-pass filtering at the reconstruction (D/A) stage, which keeps the time domain response very accurate.

I guess this is a reasonable assumption from experience.
Now, from my measurements, I see distorsion of the test tones higher than -60dB and that was for a -16dBFS tone. I’m not saying it’s related to DSD noise shaping, but that level of distortion is really unusual with PCM. I would need to feed the Denon from digital in with a 15kHz test tone and capture up to 96kHz to check if that comes from the DAC. But I don’t think I can sync at 192kHz out and in with my interface.

 

[NTTY]

Most probably this one : https://www.audiosciencereview.com/...p503e-universal-player-2005.10016/post-272016

It contains frequency sweep to assess frequency response, single 1 kHz tone from 0 dB SA-CD to -160 dB SA-CD, 19+20, 39+42 and 83+85kHz twin tones, ...etc.

Cool, thanks, I’ll try to find one.

 

[Scytales]

Good luck!

For almost 20 years, I have been trying to spot one without success!

I once found a second source, some 15 years ago: this disc (and other test discs dedicated to quality control on SA-CD production line) had been licensed to an Indian optical disc producer (Moser Baer). But the price was prohibitive (100 US dollar a disc, I still have the 2002 price list), and at that time, I thought I couldn't afford to buy. Today, I regret not having seized the opportunity.

Moser Baer is still in business and I contacted them few months ago, but they answered me that these SA-CD test-discs are no longer in production.

 

[NTTY]

Thanks for the info, it looks indeed unobtainable, too bad. Searching for the disc, I found that Archimago talked about it and was able to get some tracks from DSD original files apparently (via Black Elk).

BTW, and not related to the above, I added, in the initial message of the review, a measurement of 1kHz @-6dBFS as it shows distortion has decreased with level, and is in par with the recent Denon DCD-900NE. I thought it'd be interesting to know what happens a little lower and good to know that this is indeed a very low distortion DAC, below full scale.

And to compare with the Marantz DR700 which I also reviewed, it would show the below (again overlaid with the Denon DCD-900NE, acting as the reference):

There's a lot more distortion (+20dB), not to mention noise. Do you think it's relevant?

--------
Flo

 

[Scytales]

View attachment 392399

There we see the (shaped) noise but also distortion as high as -60dB.

Would you know what test SACD disc they use?

Cheers

--------
Flo

As I see that the third harmonic of the 15 kHz tone is about -70 dB under the fundamental, within the dynamic range and measurement bandwidth of my old Hewlett Packard 3581A wave analyser, I just searched this harmonic out of curiosity at the output of two of my SA-CD players playing the same track of this Denon SA-CD test-disc: a Sony SCD-555ES and a Marantz DV-12S2. This two players have vastly different digital to analogue converters and output stage designs.

With the Sony and from the stereo track of the test disc (right output), I have found a faint evidence of an harmonic tone above the noise floor at about -70 dB under the level of the 15 kHz test tone, but the wave analyser has not been able to lock reliably on any frequency to give a precise reading.

At the output of the Marantz and with the multichannel track of the test disc (surround left output), the analyser has unequivocally locked on a tone at 45 kHz at about -57 dB or so under the level of the test tone. With this player, I had to reduce a bit the input level of the analyser, otherwise the input saturation indicator lit up, probably because of the level of the ultrasonic noise produced by this very wide bandwidth player.

It seems that ASR member @GXAlan has the tool to analyse the digital files on this Denon SA-CD: https://www.audiosciencereview.com/...-10-review-sacd-player-dac.31686/post-1532634 (see the eighth graph from the top of his message).

Perhaps he could check if the 15 and 30 kHz test tone on this Denon disc are clean.

What makes me suspicious is that the Marantz DV-12S2 has been extensively measured by Miller Audio Research with its own audio analyser and no harmonic distortion was visible above the DSD shaped noise within the measurement bandwidth of the analyser with tones at -3 dB under the full scale output from 10 kHz to 50 kHz: www.milleraudioresearch.com/download/reports/feb04/marantzdv12s2.html

 

[Scytales]

By the way, as I speak of GXAlan's analysis : if you look closely his graph illustrating the 1 kHz@-16 dB tone of the Denon disc in the digital domain, you will find that most of the spray of harmonics and other spuriae visible on your FFT are actually on the disc! Only the third and perhaps fifth harmonics seems to be the product of the Denon output stage non-linearity, as well as a tone at 2.5 kHz.

 

[GXAlan]

It seems that ASR member @GXAlan has the tool to analyse the digital files on this Denon SA-CD : https://www.audiosciencereview.com/...-10-review-sacd-player-dac.31686/post-1532634 (see the eighth graph from the top of his message).

Perhaps he could check if the 15 and 30 kHz test tone on this Denon disc are clean.

Will do. The tool is Multitone from @pkane. You just have to drag and drop the file onto the window.

 

[Scytales]

Hurrah!

Thank you!

I wonder if there is a difference of quality between the stereo and multichannel tracks of this disc.

 

[jdg78]

So what was DSD really for?
Was it a stillborn technique... born in the minds of technicians who thought "analog" because they felt that PCM was less "musical", less "natural" than analog sound and therefore than DSD? It's not impossible... I've worked with technicians professionally who still think so...

This summer I heard on France Musique, an old radio archive: an interview with the founder of Harmonia Mundi who makes this anti-digital and therefore anti-CD speech... and who was one of the first to publish. ..SACD...

This story of DSD and SACD is strange.
Funny thing: the first publisher to have published a purely DSD SACD was Lyrinx, a small publisher from Marseille: with the help and support of Sony Electronics who lent it a Sonoma station and promoted this disc in these terms... But curiously not Sony Records... whose director of the French branch told me that "New York doesn't want to let us publish any here."

I remember the introduction of the DSD/SACD format quite clearly, and took an interest in it at the time (primarily because of the multichannel capabilities). I still have about 200 or so SACD discs, though I almost never play them.

I believe it was primarily a play by record companies hoping to hook consumers on a new format in the hopes of injecting life into physical discs in the face of declining sales. The introduction of the CD in the 80's had led to a decades long gravy train for record companies whereby they could reissue their entire back catalogs in digital format at $20 per album and rake in huge profits. By the early 2000's, the reissue well was starting to dry up, mp3's were beginning to threaten sales of physical discs, and they needed some new game changing technology to keep the good times rolling.

Hence the introduction of DSD/SACD, which was marketed as a sonic and technological advancement on par with the transition from LP to CD. They were hoping consumers would adopt the new format with the same enthusiasm as the original compact disc, and allow them to take a 3rd dip from the well as everyone upgraded their music collections from CD to multichannel SACD.

It ended up being a complete bust. Most consumers found CD sound perfectly adequate and didn't want to go through the hassle and expense of upgrading their systems to be multichannel capable. Apple introduced the iPod and iTunes store allowing consumers to buy single track mp3s, and avoid having to pay $20 for a full album when they only wanted one or two tracks. Sales of physical discs kept tanking, eventually streaming was introduced, and the rest was history.

When executed well and played within a proper setup, multichannel SACD recordings can sound spectacular, conveying an increased sense of space, depth and presence. But it requires a hefty investment in both equipment and physical setup, and was never destined to be anything more than a niche format.

At the end of the day, most people just prefer to listen to Spotify through a pair of Airpods.

 

[Scytales]

Well written contribution to the debate, jdg78.

May I ad that the professional organisations of the recording industry of Europe, Asia and America were in search of a new format based on the then new Digital Versatile Disc (DVD) to supersede to the CD. They regrouped under the umbrella of an International Steering Comity (ISC) that issued a specification for a new digital disc format in 1997.

The key requirements set by the ISC were (from the following articles) :

1. DVD audio discs should be compatible at a practical level with existing CD players ;
2. the extra capacity in the disc afforded by DVD technology must be used to achieve multichannel sound ;
3. a new active copyright management system and other anti-piracy measures must be incorporated in all DVD machines to ensure comprehensive protection of music rights holders.

Some articles of the time about the role of the ISC :

CD The Next Generation: Super Audio Compact Disc

Sony's proposal for a next-generation CD format — the Super Audio CD — promises a great deal in terms of sound quality and compatibility. But will it be enough to succeed in a confused and fragmented market place? Hugh Robjohns examines the new format.

www.soundonsound.com

RIAA specs for DVD to bow in Dec.

The Recording Industry Assn. of America said the international steering committee, which represents the industry on Digital Videodisc matters, would have a final draft specification for a DVD music disc by December.

variety.com

AUDIO FORMAT IS AGREED FOR DIGITAL VIDEO DISKS - Tech Monitor

Record companies and consumer electronic manufacturers took another step forward last week in agreeing the broad technical guidelines for the…

www.techmonitor.ai

 

[Descartes]

This is a review and detailed measurements of the Denon DCD-SA1.

View attachment 391583

As I already wrote in my previous reviews, I like testing CD Players, especially older ones. This is one more proof. My firs review of the Onkyo C-733 here contains information about my measurements which I try to align with the AES standard. It means that, over time, you can compare the devices I reviewed.

This is my first review of an SACD player, but really my interest is into CD Players, so that’s an exception I made as I needed to know what SACD (and its DSD format) had to offer.



Denon DCD-SA1 - Presentation

Released in 2005, nearly 20 years ago, it was top of the line CD/SACD player at a staggering price (7’000€+ in Europe). This player is one of those “statements” from the big Japanese names, as they like to produce them from time to time.

The conversion is performed by two BurrBrown DSD1792 stereo DACs which were state of the art converters at the time (PCM 24bits and DSD compatible).

Being a Denon, you already spotted the in-house digital filter in the “Advanced AL24 Processing” version here. This is the internal oversampling filter from Denon. It is to note, though, that the AL24 is deactivated when playing SACD (DSD) disks, since it works only with PCM data, of course. It is of equal importance to know that the player offers a mode where we can convert DSD to PCM and so benefit again from AL24 processing, which is interesting.

View attachment 391584

As an SACD player, we can play CDs, of course, and the Denon DCD-SA1 adds to that two digital inputs to benefit from its internal DAC. I like to see that possibility on CD players.

RCA and XLR are present, as we would expect.

Weighting an incredible 22kg (48.5lbs), this alone talks about the build quality. The top cover weights 3.5kg (7.5lbs) and is made of a top aluminum thick layer with copper bottom plates, both rubber-isolated in between, and all of it is of course decoupled from the sub-frame via several silent blocks

View attachment 391585

A special attention was given to power supply and isolation from vibrations. I let you have a glimpse at the inside and you can also look up on the web for more details about the engineering that went into this player:

View attachment 391586

The two power transformers are placed in an aluminum housing filled with resin in a two-steps process so that they are decoupled from their respective casts. Additionally, the two aluminum housings are again decoupled from the chassis using rubber material of different resonance to kill mechanical vibrations:

View attachment 391636

It is an absolute delight to use this player. Each button on the front face reminds you of the price you paid. The drive is also very fast which I like a lot.

View attachment 391587



Denon DCD-SA1 - Measurements (Analog outputs - From CD)

From now on, I will be consistent with my measurements as I described them on the Onkyo C-733 review. So over time, this will help comparing the items I reviewed.

From RCA, the Denon DCD-SA1 outputs 2.134Vrms, that is 0.6dB above the usual 2Vrms. The XLR output is very close at 2.09Vrms.

Let's start with the standard 1kHz sine @0dBFS (dithered) from my test CD (RCA out):

View attachment 391588

Left and right channels are shown but only one gets evaluated in that view. Both channels have the same performances, though. Plot is on H2 (-97.6dBr and -99.5dBr).

THD+N is limited (and so is the SINAD) by the dither noise present on my test CD. It's the best we can get. It shows 92dBr on the dashboard, but that is because I decreased the input gain of my interface to respect my own protocol which I documented with the Onkyo C-733 review. The truth is 93dB.

And by the way, proof of that is if I measure the XLR out, and because of 1dB difference in the input gain, THD+N is now 93dB:

View attachment 391589

Note that the THD is a little better on left channel because H2 is very much lower (-116dBr vs -102dBr).

Basically, all measurements are nearly identical between RCA and XLR, so I won’t make a difference between them in the rest of this review.

And starting with this review, I am tempted to add a measurement of 1kHz @-6dBFS to show if and how THD improves:

View attachment 392428

THD goes down to -110dB. This is an overlay of the Denon DCD-SA1 (the one measured in the dashboard) with the Denon DCD-900NE (trace only) that I propose to use for reference in this view. I think it will be interesting with other CD Players. What we see is a neat trace with very low distortion as soon as the signal decreases in intensity.

Other results (not shown) are:

• Crosstalk : -133dB at 1kHz and 10kHz (thanks to conversion in mono-mode).
• SNR : 97.3dB (1kHz @-60dBFS, no dither)
• IMD AES : -94.dB (18kHz+20kHz 1:1 @-5dBFS)

If you compare with the Denon DCD-900NE, you see that we are very close. Basically that is nearly the best we can get from CD Audio.

I suppose you saw a very silent power supply above, so all the efforts from Denon there paid off. RCA only showed a very small power supply related spike at 50Hz (I live in Europe) and at a very low -125dBr. XLR outputs showed nothing, which means better rejection of power supply related noise:

View attachment 391591

Bandwidth measurements showed a gentle roll of at 20kHz (-1dB) starting very early (10kHz):

View attachment 391593

This is exactly the same as seen with the Denon DCD-900NE and that is logical because it’s an effect of the Denon AL24 oversampling filter. I’ll come back to that later.
I was disappointed to see a 0.2dB difference between the two channels (same with RCA and XLR).

Multitone test showed no issues:

View attachment 391594

CD Audio content is more than safe from distortion, no surprise considering the previous results.

Jitter test (16bits/44.1kHz) is nailed too, exhibiting a beautiful trace:

View attachment 391595

Red trace is what is on the test CD (digital output), it can’t be better. The Denon (blue trace) does not add any jitter and really minimal noise.
If you go check the Denon DCD-900NE review, you will see the same, meaning that the few very low level (blue) spikes come from my measurement interface, not the player.

And I forgot to add one of my favourite measurements, the THD (excluding noise) vs Frequency at @-12dBFS:

View attachment 391596

The Denon DCD-SA1 had no issue here, it is the best trace that I have in my collection of this specific measurement. This an easy test for advanced 1bit DACs. I like this measurement because it shows lack of linearity already at this level with older R2R architectures, and some lower resolution 1bit architectures too, that I enjoy testing.


Denon DCD-SA1 – AL24 measurements

As with the Denon DCD-900NE, I think the Denon proprietary oversampling filter deserves a specific section, as it finds its roots back 3 decades ago.

As @bolserst wrote some time ago ago about Denon filtering, the first iteration of ALPHA processing featured an automatic filter selection based on LSB toggling, and which I could replicate too. Subsequent version of ALPHA processing included further intelligence in terms of filter selection.

I'll try to keep this section as simple as I can, but it's a challenge (again). The situation is actually the same as with the Denon DCD-900NE. So, I’ll use a different standardized test, to show the same behaviour.

First, this is the filter response (from white noise) overlaid with the standard CCIF IMD test (19kHz+20kHz 1:1) which a lot of reviewers like to use:

View attachment 391598

At the moment, please forget about the filter response (in blue) between 60k and 72kHz.

Now, those of you used to perform and/or look at these tests will see an impossibility here. It is an obviously slow filter response (as we can see from the white noise), and so it's not logical to see total absence of aliases of 19kHz and 20kHz which would show up at 25.1kHz and 24.1kHz respectively.

Well, that is because the Denon (its AL24 filter) recognizes the typical test tones and switches to a sharp filter in that case, which would make people like me (theoretically) happy. Fail

To counter the test detection by the filter, it is enough to add a third test tone with this standard CCIF test. So adding a 9kHz test tone defeats the detection of the AL24 filter, and here below we get what we should:

View attachment 391599

Very much different, indeed! This time we see what's logical with a slow filter response: aliases of 19kHz and 20kHz replicate around 22.05kHz. So you find them at 25.1k and 24.1k respectively. The same goes with other standardized tests such as AES, DIN. When “detected”, the AL24 filter switches to a sharper mode, to exhibit what testers like to see : absence of aliases out of band.

Also, as with the first iteration of ALPHA processing, it detects square signals and switches to NOS (Non Oversampling) mode in that case. This allows Denon to show perfect square waves. When looking at the same in frequency domain, we get this:

View attachment 391600

This is beautiful and could be used by a teacher at the university to talk about D/A conversion and its effect on creating aliases, enveloped into a sinc function. This garbage is on purpose, only to show perfect square waves, when requested.

The two filter modes I showed, Sharp and NOS, are not activated during music playback. Their purpose is only to shine during very specific tests.

As I commented about the Denon DCD-900NE, this has been ongoing for decades and continues today. If you want to go deeper into this, I recommend you to read the Denon DCD-900NE review, as it is exactly the same, and I already compared this DCD-SA1 with the DCD-900NE.

About the situation between 62kHz and 72kHz, that has minimum effect when playing music. Again, please check the Denon DCD-900NE review, I’ve put measurements, they are the same with the DCD-SA1. Even if it's not clean, we shall not worry too much about that specific noise (it will remain at very low level, ie -100dBr).


Denon DCD-SA1 - Measurements (Optical Out - From CD)

Some of you like to know if the player can be used as a transport. So I measured the digital output, from my test CD.
The below view shows what's on the test CD (1kHz @0dBFS):

View attachment 391601

It can't be better than that, this is what's recorded on my test CD.

Equally, and again about the digital output, I already suggested here the use of an undithered 1kHz sine at -90.31dBFS to verify the quality of the drive, should we have doubts. With 16bits, the signal should appear (on a scope) as the 3DC levels of the smallest sign magnitude digital signal, which is what we get with the Denon:

View attachment 391603

This, and other measurements I performed on its digital outputs, made me confident that the Denon is a prefect transport for those who want to use it with an external DAC (for CD audio only, of course).


Denon DCD-SA1 - Measurements (Digital In - RCA out)

Very quick feedback about using the digital inputs of this player with higher resolution PCM input.
The THD does not change (of course) and the noise improves because of the bit depth increase. Unfortunately, with "only" 2Vrms output, my interface (Motu ultralite mk5) reaches rapidly its limits (because of no auto ranger like an AP, it would be much more at ease with 5Vrms at least) and so I essentially measure its noise floor:

View attachment 391605


The noise floor is lower, but again I can’t measure it reliably. What I see, from playing with dither at lower levels, is that the noise is below -105dB, and so that is very good for the time. Power supply spike appears from the reduced noise floor (and because of 256k FFT length + 32 averages) at below -130dBr (I say negligible ).

One thing I did not mention, because I’m keeping it for the SACD measurement section, is that below full scale (0dBFS), the THD performance increases. Let’s have a look.


Denon DCD-SA1 - Measurements (Analog outputs - From SACD)

For these tests, I used the Denon Audio Check SACD. There are only so few test tones on that disc, but it’s informative anyways.
The test SACD of Denon contains test tones at -16dBFS. It’s far from the 0dBFS we (and I) are used to use. That does not help for comparison, so I had to adapt to that.

First our regular 1kHz test tone at -16dBFS (XLR out):

View attachment 391607

Pay attention to the fact that the trace in dB relative (dBr). Since we are at -16dBFS, this has the effect to visually increase the noise floor by 16dB.

At this much lower level than full scale, we see that THD remains below -100dBr, which is very good.

The calculated noise floor is around -105dB which I’m sure is the noise floor of my measurement interface. Indeed, because the Denon output “only” 2Vrms, I have to increase the input gain of my interface by 15db! This is to respect my own protocol of measurements to get the ADC of the interface close to 0dBFS when capturing data. This allows me to get dashboard measurements from REW software that are correctly calculated, especially the ENOB. Since I’m almost only measuring CD Players, this limitation is not a problem, as a 16bits test tones with dither (which I use) have a noise floor of -93dB. Of course, here the SACD (DSD) lower bit depth puts my interface in an uncomfortable zone. On one side, that is good news for the Denon DCD-SA1.

If I go more into SACD testing, I will need to figure out a way to increase the voltage before feeding my interface. I suppose I could use an extremely transparent Preamplifier to do that. I’ll report here if I get there.

All that said, and since the Denon DCD-SA1 offers the possibility to convert DSD to PCM on the fly, and therefore benefit from the AL24 filtering, let’s see if that changes something;

View attachment 391608

Well, no. But that’s not all.

Let’s play a nasty game. I remember at the time of SACD release, I’ve been told that the extended bandwidth of DSD was a major improvement, along with the increased bit depth. If I can already testify on the later, not yet on the former.

Because of its nature (1bit stream) the DSD generates a lot of mathematical errors, say imprecision. Noise shaping comes into play to reduce these errors and to reject them out of audio band (beyond 20kHz).
So, let’s have a look at a measurement of the same 1kHz sine (still at -16dBFS) but using a wider bandwidth, up to 48kHz, allowing the software to calculate noise and distorsion up to 48kHz:


View attachment 391611

Hmmm, what we see here is a lot of noise created as soon as we go over the 20kHz theoretical limit of our ears. This is an effect of Noise Shaping. So what’s preventing a lot of noise in audio band is creating a lot of noise out of audio band. And that’s really a lot, because if you look at the dashboard, and I left it calculate the noise and distortion up to 48kHz, this is a huge difference. The calculated ENOB is now 10.5bits, ouch...

This typical noise accumulation, out of band, can be found on all tracks of the Denon Audio Check SACD.

Now, let’s try when converting DSD to PCM before feeding the DACs, which means the AL24 filter kicks in too. Here you go:

View attachment 391612

That view demonstrates that the noise generated by the noise shaping technique is part of the test Denon test SACD, it’s not generated by the player. When converting DSD to PCM, the AL24 improves the filtering by removing this out of band noise present on the track (not all, but some of it). ENOB improves by 2bits.

Last and not least, let’s feed the same test tone, but this time from my interface (24bits/96kHz), directly into the digital input of the Denon (and therefore in PCM, of course):

View attachment 391618

And voilà, despite noise included up to 45’600Hz, we keep very close performances to what we initially saw when limiting the calculation at 20kHz (again I’m nearly sure that Noise is limited by my interface).

Is that a fair test? Yes and I no. Again, I remember the promise to get more than the CD limitation at 20kHz from SACD. But if it is to get that amount of noise, I wonder.

Because again, when playing pink noise or music from the Denon Audio Check SACD, I see the same noise on all tracks. This is below an analysis of musical content (1700+ FFT averages over more than 5min) with Pink Noise:

View attachment 391620

The track (#27) in the Denon audio check SACD is Mahler: Symphony No. 2 in C minor "Resurrection" - 5th movement closing part (F.!) (Conducted by Wenceslav Neumann, Czech Philharmonic Orchestra, the choir, Gabriela Benachikova-Chapova (soprano), Eva Landova (alto))

I overlaid the SACD layer (green), CD Layer (red) and conversion from DSD to PCM (blue) of the same track to show the differences. This is in Linear Frequency Scale for a better view. Here we see that the only potential advantage of SACD is between 20kHz and 25kHz where noise is still below musical content, From 25kHz on, the shaped noise of the SACD track takes over.

Of course, that is from Denon test SACD. But isn't it supposed to be a disc containing “reference” material? If yes, can we get better than that?


Conclusion

That was a long review! Thanks for those of you who made it!
How to conclude?

• Used as a CD player, in audio band, these are very good results for a 20 year old player, nearly best in class. Distortion could have been better, yes, for those who can hear -100dB distortion relative to 0dB signal.
• Used as CD transport, it is flawless, no surprise (only CDA).
• Best performances are obtained from digital inputs, thanks to Denon to let us benefit from the DAC’s full performances as we want. No DSD input though, but I guess the DSD to PCM convert will make you think about the real need for that feature.
• The behaviour of the AL24 filtering is funny, designed to shine under measurements. It's been ongoing for a long time. The Denon DCD-S10 was already including some tricks and the very new Denon DCD-900NE carries that heritage.
• This is an incredibly well-built CD/SACD player, I love it, one we see once in a decade. It’s still alive and kicking!
• SACD measurements left me wondering what was into this move from Sony and Philips. I did not see anything tangibly good for me, especially knowing that I used a referenced SACD Test disc for the measurements, which I suppose has been created with great care(?).
• Noise shaping techniques have improved, allowing the theoretical 16bits of CD Audio to be actually much lower. What's left to SACD when compared to CDA is that extended bandwidth which I did not find here, at least from the Denon Audio Check SACD.
• Anyone who participated in the engineering, product design and approval of such a piece of art, shall be proud and must be thanked.

I hope you enjoyed the long review and, as usual, let me know how to improve and if you have questions. I have recorded all the 44 measurements for both XLR and RCA outputs (and much much more). And if you want me to publish others or run one of your choice, feel free to ask.

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Flo

Magnificent piece of art and engineering!

DCD-SX1 LIMITED | スーパーオーディオCDプレーヤー | Denon公式

DCD-SX1 LIMITEDの製品詳細ページです。サウンドマネージャー”山内慎一”が4年の歳月をかけて作り上げた新世代のフラッグシップSACDプレーヤー

www.denon.jp

This was their super flagship (which appears to be discontinued?).

891000 yen!

Approximately $6,900

 

[NTTY]

It seems that ASR member @GXAlan has the tool to analyse the digital files on this Denon SA-CD: https://www.audiosciencereview.com/...-10-review-sacd-player-dac.31686/post-1532634 (see the eighth graph from the top of his message).

I'm not much used to that tool, but I tried to replicate (512k FFT, BH7, 128 averages, 93.75% overlaps) with the 1kHz from the Denon SACD test (track #12):

The trace is very similar. For some reason Multitone does not want to extend the view to 96kHz.
Noise floor is a little higher which could very well be my interface, again not at ease with only 2Vrms input, not to mention with -16dBFS test signal here.

Lots of harmonic distortion, all those spikes (odd harmonics) in the shaped noise are multiples of the fundamental, same as what we can seen with @GXAlan. I left the cursor at 27kHz which shows an harmonic at -98.8dB. It could be on the Denon SACD indeed.

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Flo

 

[GXAlan]

For some reason Multitone does not want to extend the view to 96kHz.

The second to last icon next to the red X on the upper right should let you adjust your frequency response that is displayed.

Additionally, you should be use the scroll wheel when it is over the axis in order to zoom in and out.

 

[NTTY]

Will do. The tool is Multitone from @pkane. You just have to drag and drop the file onto the window.

Cool. Do you mean that you record as a WAV file and then replay?

 

[pkane]

The trace is very similar. For some reason Multitone does not want to extend the view to 96kHz.

It's actually going out to 96kHz on the right side of the chart. The last label didn't fit and was not displayed because of that. You can zoom-in on any portion of the chart to see more X or Y axis labels that might be missing in between or at the end. Use the mouse scroll-wheel to zoom-in, but first position the cursor over the part of the chart that you want to zoom-in on.

 

[GXAlan]

Cool. Do you mean that you record as a WAV file and then replay?

Yes. If you record the output from the SACD and then drag that file into multitone, it will do the analysis.

What’s even cooler is you can use DeltaWave to compare the ripped file against the recorded file!

 

[NTTY]

Thanks @GXAlan @pkane

I tried recording a wav with Audacity, but it looks like the export adds low level distortion. As I'm not used to that Software either, and I did not investigate yet. That said, to record with Audacity, I had to use the front line inputs of my interface (Audacity does not see the others by default and I don't know how to activate them). Because the sensitivity of those are 4dB less, that's an avdvantage and so the measurements slightly improved (by roughly 3dB). H3 is much lower, though, so that's good news too.
Anyways, here are 3 measurements from the Denon Test SACD, at 1kHz, 10kHz and 15kHz (64 averages this time, but in the future I'll go back to my standard 32).
Let's start with 1kHz @-16dBFS:

I did not manage to find a way to represent in frequency linear scale. All measurements have improved a little, which proves my interface was and is the limiter.

Now 10kHz @-16dBFS:

I let the software calculate distortion and noise up to 96kHz, but that was only to have the plots of harmonic distortion (H2 to H8).

Same with 15kHz @-16dBFS:

I'll let you confirm @GXAlan but at 1kHz our traces are the same, when it comes to distorsion starting at 10kHz. I guess you'll find the same as mine at 10kHz and 15kHz which would probably mean it's part of the Denon test SACD (else we have exactly the DACs in our respective players).

EDIT: I've put my hands on a Pioneer PD-30 SACD player, and besides a small leak from the power supply, the traces are the same, so I'd say it what it is on that Denon test SACD.

1kHz:

10kHz:

15kHz:

Cheers.

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Flo