CD Quality Versus Streaming Quality

I realize this will be a contentious subject, and far be it from me to challenge any of the many expert opinions on this forum, but if I may offer my feedback vis-a-vis what I am hearing, and gain some knowledge in the process.

i will begin saying that my digital front end setup is not state of the art, but i have had the good fortune to listen to a number of really high-end systems. I guess the number one deficit in my digital front end is a streamer server, and no question about it that will improve the sound.

My CD player is a universal player; Pioneer BDP-09fd. It uses Wolfson DACs. It has been modified to a degree. I have bought and sold other players, but kept this one, because it has a beautiful sound that serves the music well.

Recently, i ventured over to my son’s place and we hooked up my player (he doesn’t have one and rely’s on streaming only) We compared tracks / albums of CD quality and master quality streamed on Tidal with ‘redbook’ CDs I have. For example, some Lee Ritenaur CDs and some Indian classical and the wonderful Mozart and Chopin.
His system is highly resolving.

we were both very surprised to find the CDs played on the player to be the better sound. And not just by a little. The sound was clearly superior, with higher resolution and definition, spatial ques, much better and clearer imaging. Very surprising indeed. Shouldn’t there be no difference? This would suggest the streaming service is throttling the bandwidth or compressing the signal?

i am most interested to hear others’ observations, and suggestions as to why this might be? I do love the convenience aspect of streaming, but it IS expensive for a chap like me of fairly modest means. The Tidal HiFi topline service is $30 per month I believe, something the good lady is not too thrilled about. God forbid I should suggest Roon on top of that I may likely get my walking papers. I jest, but only partially LoL. My point is, if I pay this sort of money, isn’t it fair to expect sound to equal the digital stream from the CD player and silver disc?


CD players have been put down due to a lot of advertising of the next and best thing: streaming. I’ve read countless posts and articles about all the things that can go wrong with CD playing and that streaming was the cure. Perfect sound forever, this time around.


All the best,
+1 nonoise! It's anybody's guess what the provenance of a particular streamed music track is! 

Streaming usually uses the later released versions of the same album, which are highly compressed and it saves them money on bandwidth space (more $$$ for them), compared the the original uncompressed ones from years ago.

Proof here with links in the last few posts starting here near the bottom with my post on Elton John’s "Madman Across the Water".
Cheers George

Well the earlier uncompressed "used" ones are now demanding far more than what they were new on ebay. So you know the streaming companies aren’t going to shell out for those. They are going to go for the cheapest they can get, which unfortunately is going to be the later/latest highly compressed versions.

Just look at this, which do you think the streaming company will end up getting 28 years difference for the same CD only the oldest one is uncompressed. Look at the shocking difference in dynamic range!!

Cheers George
My SQ rule based on my experiences!
Original LP
Remastered analog or digital LP
Hi res Tidal streaming

this topic has been explored in many threads here.  Personally I see no reason why one digital technology should be better or worse than another.  A CDP can extract the bits and send it to an internal DAC, leaving all the streaming issues aside, such as provenance of the masters, the quality of the streaming service, whether the ISP is throttling bandwidth in this era of Zoom and everyone getting all of their entertainment over the Internet, the home router, and the quality the streamer.  For me, given all the links in the chain just described, the wonder is that streaming can sound as good as it does, but the claims that it inherently is superior to CD replay are just marketing blather 
As noted above, music is often re-mastered for streaming, making direct A/B comparisons between those and the original CD's very difficult. Whether hi-res is audibly superior to to Redbook is still an open question in my own mind.

MQA is another whole can of worms. Many contend that MQA "folding/unfolding" is not a lossless process, and some artists have removed their catalogs from Tidal, because the end result was not to their liking. Tidal maintains that MQA content must be played back through proprietary MQA-licensed gear to achieve a complete sonic "unfolding".

I've personally opted to stream hi-res for my own system from Qobuz, rather than Tidal. Qobuz offers FLAC content quality up to 24/192 for many releases. Another streaming alternative is Deezer, which provides CD-quality content streaming. Subscriptions to both Qobuz and Deezer together can be had for less than the price of a top-tier Tidal subscription.

Let everyone go to streaming. I will continue to happily scoop up their unwanted CD's at goodwill gfor pennies on the dollar, just as other people did years ago with LP's.
Vinyl, Redbook CD, and hi-res streaming aren't mutually exclusive. One would need need to pry my extensive Redbook collection and all of my old records from my cold, dead grasp.
It would be nice if every audio recording had something like a VIN number, so that it could immediately be compared with another (supposedly) "same" recording.
It is not the technology, it is the mastering of the music.  Even with CDs, you can find early CDs that sound MUCH better than later CDs because of the change in mastering.  A lot of more recent material is, as others mentioned above, very highly compressed.  This is actual desirable for those who listen casually, listen with earbuds while in high noise environments, listen in the car, etc., but it sucks for those who want higher quality sound.  It is really not the fault of the music industry; it is the public that actually favors compressed music.  If you want the best digital source material, you have to actually seek particular CD issues or download files from sources offering high quality material.


You have opened up a can of worms :-) I see same old folks, hopping from one thread to another cascading their stale biases.

BTW, if you invest time and efforts in a good streaming setup, you will be rewarded with sound that equals or better than CD’s. And you can have high resolution streaming (Qobuz) for as low as $12.49 per month.
As far as I can tell, you were using 2 different DAC's and therefore hard to do a direct comparison.

A better example might have been to use the Pioneer's digital outputs to the same DAC that was doing the streaming.


A couple of issues to consider in your listening test with your son’s system.

1. From my experience, Tidal is the worst sounding of all of the major streaming services. My impressions of the sound quality of streaming services is:
1. Qobuz
2. Primephonic
3. Spotify Premium (320 kbps Ogg Vorbis which is not lossless)
5. Amazon HD
6 Tidal

2. Analog noise in the form of EMI and RFI has a major impact on the sound of digital. What source did he use for streaming? If it was a PC or Mac that could be a reason why streaming sounds much worse.

Now I will admit that I replay digital music from both local files and streamed through Qobuz (and some Spotify Premium). Local files DO still sound better to me presumably because local files attached to my streamer have a shorter signal path to my amplifier than files streamed via the Internet going through Comcast’s cables through my WiFi router, etc. BUT, I found that these changes that I’ve made to my streaming signal path all have made a noticeable improvement in sound quality to a degree that streaming music is quite enjoyable.
1. Switching from WiFi on my streamer to Ethernet via a TP-Link RE230 WiFi extender
2. Switching from an AmazonBasics Cat 6 cable to a Supra Cat 8 Ethernet cable (~$70)
3. Adding an Audioquest Jitterbug noise filter onto the USB output from my streamer
4. Using a Stordiau Lush USB cable (~$200)
5. Using a Shunyata Venom power cable ($135) on my DAC
6. Linear power supply instead of a switch mode power supply for a streamer. I haven’t tried this yet because my Pro-ject streamer is supposed to benefit less from this change.

The reason why all of these changes have improved the sound is because they help block EMI/RFI from getting into the signal path. As I heard, Darren Myers, analog engineer at PS Audio, say on his Hi Fi Podcast just this morning: Getting digital audio to sound good requires more than just plug-and-play. Every component in the digital signal path can matter and setting up digital audio for good sound is as complex as setting up a turntable and cartridge.

My perspective is that even if you can’t get streaming to sound quite as good as CDs, the ability to hear all sorts of new music is really fantastic.
CD vs streaming quality 

CDs use land and pit to read the impressions (grooves) made by a laser as 0s and 1s. 

Streaming with Wi-Fi is pretty good. New iterations of Bluetooth 5.0 that include other codecs above 320kbps may sound identical to CD quality for the average person.

A good CD player can match or best many DACs out there. CD players don't have the same latency problems/EMI that DACs have. If your CD player is really good, you should be able to seek (go forward or backwards) instantaneously; where the track dial is very fast.

With CDs, there is no additional software, cables, or programs to worry about. Anything within this chain could change sound quality for better or worse.

A good example - foobar vs Jriver. They don't sound alike when configured (options) at all.

I just don’t get it, those pro to streaming/downloading just don’t see this??.
Or are they that blinded by streaming/downloading now they just can’t bear to look at it to see what’s happening to the uncompressed/dynamic music they once loved.

I had many audiophiles friends that don’t come to our Audio Society club meetings anymore, that had mega systems and cd collections and have gone by the way side now after selling their music collection and stream now through far more mediocre systems.

Cheers George
That's sad. Why do so many praise streaming then? I guess it's for the convenience.
I think maybe it’s because they sold all their thousands of CD’s to go that way and now there’s no return.
But I’ve noted many never sit still on the streamers they always complain about something it or the streaming company not being right and want better with it.

Cheers George
For equally quality systems, in general, a red book CD is indistinguishable from the streamed version on my system. This was true for my previous system as well. Perhaps there are a few that have different files being used… but that is an exception not the rule. if I absolutely love some late 1950’s jazz I’ll pull out my vinyl copy, which gives me the last word in fidelity.

I use Qobuz, but used to use Tidal. This is not a question of one sounds terrible… they sound very similar… you would have to spend a lot of time to come up communicable differences, your equipment choices are going to make much bigger differences. But Qobuz has more high resolution titles. The high resolutions versions generally sound better than red book. But the most determinant factor of how good the sound is, is mastering. I frequently lift my head and go, “wow, what a spectacular recording”. About half the time it is a red book cd quality.

So, with good equipment, streaming just trounces a CD player. Not for every album sounding better, though many do, but for opening up the whole world of music and much of it higher Rez. Most importantly you can stop re-listening to the same stuff, because “you own it”. It opens up the whole world of music! I occasionally listen to something again… but nothing like I used to. The streaming interface lets you “collect”the stuff you want to re-listen to so it is easy to find. And, you have to… I probably listen to three new albums a day.

So, if you are going to put effort into digital, put it in streaming. It is what you are most likely to be listening to for the rest of your life… that and vinyl (if you are into that). Well done streaming is going to sound the same or better, but open up the world of music. I have 2,000 CDs working as a diffuser on a side wall… and dust collector.
I agree that a streaming setup will never have optimal SQ until RFI/EMI is lowered or eliminated. 
The coax cable coming into the house carries with it high levels of RFI, then plugs into a modem/router which generates RFI/EMI to the audio system.
A few members here have experienced improvement by using a LPS on their routers rather than the wall-wart which adds noise from the mains and from the SMPS device itself.

I chose a different way to go by using a power conditioner with RFI/EMI filtering with my router. The improvement in SQ was most audible, the lower noise-floor being the major upgrade.

So, if you are going to put effort into digital, put it in streaming.

Trouble is very good chance your not going to get the uncompressed original releases of your last 30 years of favorites. You get the re-released later compressed ones, as I’ve shown.
Unless your very young and don’t listen to anything over a couple of years old like us old farts, as it’s all compressed these days and you have no reference to hear it uncompressed.

What would be great is a streaming company that "says" it will only stream the uncompressed old 1st releases of the music, with no extra compressing on their part to save streaming space, this could then be called
                                 "The Audiophile Streaming/Downloading Site"

Cheers George
Post removed 
Thanks all for your excellent feedback.


- We tested the BDP-09FD’s internal Wolfson DACs, and feeding the digital signal using Coax digital cable to the Expert Pro 220’s own ‘magic’ DAC. I guess I just like the sound of my player’s DAC too much. Both were really excellent. Listening to CDs from Fourplay, Bob James, Stanley Jordon and more, in each instance the results were unambiguous. The CD yielded a superior sound to mine and my son’s ears. I hate to use superlatives, but the difference was dramatic. The sound from the player / disc was altogether clearer, more consise, fuller, bigger, more effortless / less strained even when the decibels were increased to loud levels, to say nothing of definition and detail especially in the upper mid / treble hf region. Low  level listening was more resolved too. 
Mastering92 brings up interesting points re; latency and EMI. George, I think your point on mastering is very intriguing also. I will investigate.

I do understand that a full non-compressed stream should sound no different in quality between different digital formats using like DACs / amps etc. Again my streaming setup is not complete, lacking a good streamer server, although in my son’s system both Tidal and qobuz run optimally on the Devialet Expert Pro 220.
Stating old stuff here.  When cd’s came out 1 k of ram was about 1000 dollars. The red book standard for music was ahead of the means to store it or read it accurately in real time.  Reading digits off a spinning disk has inherent errors up to 5 percent depending on the condition of the disk and the quality of the transport and laser.   Dacs essentially have to guess where the missing information is based on algorithms.   Once you had cheap enough buffers like the original ps audio rom systems the errors were gone.  Now with solid media the digits can be stored without error and served yo an asynchronous dac.  No matter how good your CD player is, the process is flawed and outdated.
now there are data issues when you rip your cds to memory that are probably not audible, purchased 16/44 will provide excellent sq.
Streaming, like Class D amplifiers, are both getting better and better and at a very fast rate! 
With streaming everything matters in terms of getting great sound quality.  The software used is VITAL folks. Ridding the digital front end of noise is critical.  In the end, streaming CAN sound every bit a good as the best CD players.  Just no doubt. 
Streaming is wonderful for discovering new music much like Youtube.  However as has been stated previously your listening to overly compressed music where much of the detail has been lost. The music supplied by Tidal/Quboz are not original mixes/masters that were mostly carefully done in the 1980's by people like George Marino at Sterling Sound. Your getting what the Record Labels are currently supplying which is Remastered crapola.  Do your research instead of spreading myths.  Go buy a 1985 CD of any title you the DR to your streaming options. I doubt any of these streaming guys have ever heard a TOTL Esoteric/MSB/Luxman/DCS system with Original master recordings. Your in denial or just plain lazy. In todays world everybody wants convenience and not quality.  One of the Posters put a link in as to declining CD what does that mean?? Did you do that to prove your point that the masses are turning away from CD's because of the sound quality? Going by that logic I guess since Britney Spears has sold more Records/CD's than most of the Classic Rock bands I grew up listening to she's more talented?? LOL  

Since 1987 I have been dealing with Hundreds of people in the music industry from every possible avenue...Recording Engineers, Producers, A+R, etc  Thats how Ive gotten over 9000 Gold/Platinum Record awards (Featured on my Facebook page). These people will tell you exactly what I said above. You arent getting the Primo original recordings....especially since the Fire 15 years ago where a Huge portion of the Universal Archives went up in smoke.  You do know that there are only 3 Major Record Companies left right???...and the largest one lost Thousands and Thousands of the Masters before streaming even existed.  So what copies do you think you are listening to?? HIGH RES means nothing if the Source has been compromised.   Your never going to find the best recordings streaming for titles prior to the turn of the century.  You spend so much time stressing over your gear and what amp to pair with your speakers, cables etc....but then completely DROP THE BALL and cant be bothered to listen to the best sound possible of your favorite recordings.  In my book thats doing yourself a grave injustice. Convenience + Quality is rarely  synonymous and it sure isnt in this hobby but hey believe what you want. Your paying for your own ignorance/false beliefs based on no factual foundation.
You didnt give any data on the streaming setup or settings. Tidal, for example, has three levels of quality.  The playback is critical. So you just said, "i have a convertible, its faster than my son's sedan, therefore convertibles are faster".
Um, maybe.
you might read my crazy long posts in reply to someone;s questions re: streaming recently.
I have over 40 years in Audio as well as owning a Audio store 
I have owned pretty much 90% of most designs out there .
a cd was great in its day ,but today Waay outdated .
a disc wobbles even a small amount ,is magnified and error correction needs to work on correction error correction .
It’s ok for CDs thst are out of print , I burned mine to a hard drive 
DB Poweramp is a great way to accurately copy your discs to hard drive . The key is getting everythung done correctly with great streaming . I just purchased a Bricasti  M3 very good buy having both in the same chassis with optional Roon 
Ethernet card ,before connecting Ethernet cable ,BTW I use 
certified cat6 cables made by Beldon used in top studios blue jeans cables sell it very good cost effective Ethernet , and 
Uptone audio, Ether regen ,which totally makes a New clean digital signal right before it goes into the streamer . Use very high quality power cords , dedicated line I use a 4 wire dual ground 
one common, the other insulated,isolated ground , awg10 ,
20 amp dedicated circuits are  essential, Gold plated  Copper AC outlets . It sounds like a lot but done over time , you can hear the difference with a very good dac, and high quality streamer any short cuts your audio will suffer ,it sounds very natural and better then using a usb cable for sure and superior to cd ,clear and pure.

I've worked hard collecting my beautiful classical cd's, All top quality performances, rare recordings,,,and have zero interest in streaming.
Sorry wish I could give you a   solid opinion,, I've read here and there, streaming is not anything special.
I need a  physical cd in my hands to  connect with the music. 
Streaming is too impersonal,  somehow the  music would lose touch with my soul.
SWallowed by  the high tech thingy.

New to this argument and i know it can be done losses so what are people talking about when they refer to the “version” of the title that streaming services use vs the red book cd?   Yes it’s compressed but if it’s lossless what does that matter?  But if it’s true the version the streaming service STARTS with is compressed poorly then garbage in garbage out.  Just curious if that is true, was true in the past, and why people thinks it’s true. 
Just installed Mundorf Caps in my  Jadis JS2Mark2 DAC, Running Telefunken  ax's/au's and just installed JFET super high tech Class A opamps and will have my tech guy install Takman resistors,,Gonna be niceeeeeeee
I prefer cdp/DAC's over streaming. 
Agreed you are rarely getting  master recordings but QObuz has hirez masters 
as well as Tidal just not that  much maybe 10% or less , as I stated in a previous email , if the dac you have is doing it’s job correctly Bricasti for example is known for their excellence in the recording venue and use the older no longer made laser trimmed Analog Devises ladder dac chips just as a starting point there are a ton of many critical areas to total the sum of its parts to properly convert the Digital to Analog signal.  From there the Streamer has to correctly not corrupt 
or allow any artifacts or electrical noise in the signal path while it is sending data 
to be processed , as they say ,the end result is only as strong as it’s weakest link.
quality of all cables count Analog ,power cords, as well as digital .
it can be very stressful at seems  $$ money is always not enough .
now I am saving for a Loudspeaker upgrade, how much do I need to spend 
$10k-$20 k ? I guess we shall find out.
CD players are better than streamers for sure no contest especially on a speaker designed to handle their dynamics because almost all of today's speakers are not good enough to handle the cd at all they will compress it too much so i agree totally with your findings.
Wow riaa_award_collectors_on_facebook!

 Most impressive background. Facinating information that strikes of truth, and by that i mean good information. I am all ears and attention. What you are saying (and George too), means that many of the recordings we listening too from streaming services are already compressed? Interestingly, the CDs I mentioned above, are all at least 15-20 years old and more.

Guys I beg your pardon, but I think this subject is not stale even though it may have been talked about many times. Aren’t all aspects of our hobby talked about many times? We help each other to build better sound systems within our budgets.
Streaming and cloud storage is a huge business as is hardware and software around these services. My own monthly bill includes Tidal topline service, apple music (for family), britbox, acorn TV apple tv, and my cloud storage plan. Many ‘in the business’ do not want to move away from streaming because of huge revenues and profits. It seems nowadays that it is heresy to suggest that anything other than streaming is inferior. Incidentally, The best sound I have ever heard on multi-hundred thousand dollar systems was analog LP systems. By best, I mean the most convincing of reality to my ears. I have heard some great streaming systems too, but not as good as a high-end transport DAC Clock CD / DSD systems. If the music is served from a local server / NAS drive, I believe that is not considered streaming?
I'm one of those tone deaf doofuses who actually often prefers streamed versions of selections over my original (but not always first issue) LPs & CDs. In any case, more often than not there's enough difference between my originals and the streamed selections to make it pretty obvious that Somebody From the Future has had their way with my Analogue Treasures.  That, though, doesn't mean they're ham-handed clods.  Qobuz is particularly talented in bringing out the best of what was hiding in the originals.  Monsieur Q has a pretty good set of ears.
my ears. I have heard some great streaming systems too, but not as good as a high-end transport DAC Clock CD / DSD systems

Glad you posted this experience, which is both substantive and convincing.
I always knew digitally streamed somehow missed the power of  the music. The soul of the music. 
Kind of flat and spiritless. 
Cd will  give you the true sound of the music, as opposed to streaming's **almost as good as cd quality***, But always falls short.

I also think a  good phono can beat out ever so slight, a  great DAC. But not by much. I prefer CD, as LP's can scratch and you have to flip a  LP over after 30 minutes play time. I have cds, 85 minutes in length!!!
Former CD owner sold out to now stream exclusively and damn happy to have switched as I now listen to as much new music as I do my old music.

As importantly the switch/server/ddc/dac chain that I spent $15K on sounds as good as my buddy's $25K Esoteric K-01XD SACD player when I use it in my system.

Can't seem to really identify/appreciate the difference in sound quality between Tidal Masters and Spotify Premium so I use both, when Qobuz is available in Canada I will sign up to use it too.

Upshot being I agree with those here who say there's nothing to lose by trying out streaming, just be prepared for a steep learning curve, it took me 2 years to figure out the tech chain and how to optimize with tweaks, if that ain't your thing then yeah stick with the SACD player and disks.
Streaming on my system, there’s not much difference between Qobuz HiRes and Tidal MQA.  Tidal has more of the old school R&B music I like so I use it.  I find Qobuz SQ overall better.  I also like the Tidal interface better.

I’ve long since ripped my CD collection to FLAC on an Innous Zenith MK2 streamer.  Those sound very nice as well and better than comparable Qobuz or Tidal albums.  I have a few DSD128 albums on the Zenith as well, and they sound the best by far.  DSD64 sounds OK but no better than Qobuz HiRes in most cases.  

That said, me and my friends all agree, my vinyl rig sounds the best.  
You guys are probably think I’m goofy but I’ve been experimenting with a bunch of different stuff. I went pretty deep down the DAC rabbit hole ending up with a $10,000 Meitner. Honestly it’s hard to tell the difference between that and a $2000 mytek. So I hooked up some older equipment I had that was made back in the early 90s by DBX. It’s called a 4BX expander and it really does expand the music. I don’t know how to explain it but it was designed to undo the compression I’m guessing they put into records back in the day. It does seem to have the same affect even after the music has been streamed to a DAC and then converted back to analog. 
Back to the conversation I find streaming much more enjoyable and much better sounding than the CDs that I have. I also thoroughly enjoy finding new music, there’s so much stuff I would’ve missed if I would’ve only stock with the CDs that I have.
Don’t worry about it. Just enjoy the music in the best format that is sensible.
If you're perfectionist, a Redbook copy printed onto a gold disk often sounds better than the original. If you like listening repeatedly that is probably the way to go. If you like sampling a big part of the  recorded music universe Qobuz is the best value.
Tidal meh!
A few points.

Your original post points out the reason there is such a vibrant market in streamers and other related hardware. From the very beginning the goal was to bring streaming up to the point of CD quality. There are a lot of factors that can affect the sound quality from streaming. People spend thousands of dollars on their streaming hardware to achieve better sound quality. CD player quality has plateaued at a very high level. Streaming is still catching up.

It is a fallacy that the files that the record companies give to the streaming services are more compressed than the original CDs. There are millions of songs on the major streaming services and it is physically and financially impossible for the record companies to remaster them for this purpose. They are too cheap and lazy to do this but the main question is why would they do it? They have nothing to gain from this exercise. The 30 year old 44.1/16 Santana file you hear on your CD is exactly the same as the 44.1/16 file on Tidal or Qobuz (MQA is a different story). This has been verified numerous times. If someone found that the original file had been corrupted by further compression it would be a major scandal that the streaming company couldn't live down.

The idea that Tidal or Qobuz would compress the files themselves is also ridiculous. Their whole business model is centered around offering CD quality through their premium streaming services.

I have burned several thousand CDs using dB Poweramp (FLAC, uncompressed) and I can tell you that in my system the ripped file sounds exactly like the CD played through the same DAC. I can also tell you that 320 bit files through Spotify sound exactly as you describe compared to the same CD title. They are two dimensional with less clarity and the difference is not subtle. I'm about to subscribe to Qobuz so I'll have an opportunity to compare its sound quality to the CD version.

My overall reaction to your experience at your son's place is that something is wrong. You shouldn't have heard such a dramatic difference. But pretty soon I'll see for myself.
Interestingly, the CDs I mentioned above, are all at least 15-20 years old and more.
Yes and the later the re-issues the more they get compressed as I’ve shown. And do you think the streaming/download companies are going to search for the used earlier harder to find releases?? (no I don’t think so)

28 years difference of the same thing and what happens to it the younger it is

Cheers George
Reading digits off a spinning disk has inherent errors up to 5 percent depending on the condition of the disk and the quality of the transport and laser.   Dacs essentially have to guess where the missing information is based on algorithms.   Once you had cheap enough buffers like the original ps audio rom systems the errors were gone.  Now with solid media the digits can be stored without error and served yo an asynchronous dac.  No matter how good your CD player is, the process is flawed and outdated.
now there are data issues when you rip your cds to memory that are probably not audible,
I have worked for 10 years as software developer on making CD test disc equipment, that is for example for CD pressing plants and CD drive manufacturers.

Not many has used the physical Red book or the different orange books, for implementing measurements parameters that verifies the wording in those from Sony and Philips.
So that drive manufacturers can make sure that they can play a disc that meets the standard. And that CD manufacturers can make sure that they make discs that fulfill the requirements/standard. In those books.

A CD drive and a CD disc use many techniques to ensure that the data is error free. Will not bore you with all of the technical details. One small example, there is in the red book standard that do not allowed there to be ANY  un-correctable errors at all.
That parameter is called in the industry for "E32". It must be 0 otherwise it is out of specification.

What happens when a drive can't correct a error (that is all happening BEFORE entering the DAC) on a scratched/bad CD disc and get E32.
It puts out a error and stops reading/playing the disc.

In other words there is not a single bit that is in error from the drive that is going to the DAC. All data is fine and correct. And if the data is not guaranteed to be OK then you don't get anything. (100% correct or nothing.)

So I don't know where the horrible and completely flawed, misinformation in the quote is coming from!
I’ve kept my CDs. Starting to find out it was more than just too many very heavy boxes to deal with, but the actual treasure they once occupied in my mind. 
I was always led to believe that if an e32 was had (cannot read bit) 1 or 0, then whatever was read before was subsituted for the unread bit?.

Cheers George 
I ripped all my original CD’s years ago and stored them as FLAC files on a local NAS drive, with backup!
I have a £2000 Lyngdorf CD2 CD player and a £2500 Bricasti M5 Streamer. Playing the Coax output of the Bricasti and the Coax digital output of the CD2 into the same DAC results in the streamed version of the CD compared to the original CD sounding better. So I have better sound from my original CD’s that are now in storage, I have instant access to them all and I have no ugly walls of shelving stuffed with CD’s. I also stream from Qobuz for finding new music and listen to Internet radio with the same fantastic sound quality.
The reason it’s so good is the quality of the Ethernet network components. Ethernet Cables, RFI filters, precision switches are all critical to achieve this, unfortunately it’s not cheap to do it right.

I ripped all my original CD’s years ago and stored them as FLAC files on a local NAS drive, with backup!
You did this using "some other cd transport" from it’s digital output to your HD??

Sorry to me there is no way the streamer playing back the HD could be better through the same dac, than just the CD2 as a transport through the same dac.
If anything it should be slightly worse from the HD/streamer.

(unless there’s some wrong with the Lyngdorf CD2 as a transport it’s digital output)

CD > CD/transport? > copied to H/D> Streamer> Dac > system

CD > CD2> Dac> system

You posted this last year.
The CD2 playing the original CD is superior by some way to any of the streaming options. I now use streaming to explore my music collection, playing background music and finding new music on Quobuz. I then buy the CD and play that for a serious deep listen. That is the way to go.

Cheers George

Just look at this, which do you think the streaming company will end up getting 28 years difference for the same CD only the oldest one is uncompressed. Look at the shocking difference in dynamic range!!
@georgehifi, thanks for sharing this.  In the album details, when it says codec = flac and source = cd, does it mean that the DB measurement is done on files that is ripped from cd to flac format?