Download: FLAC, WAV ?
Posted by: allhifi on 16 October 2017
Good day, Hi-Fi faithful !
Question: I was about to do my first (ever!) music-file download; MQA (Onkyo Music) - 24/96 (FLAC) file. No other file options were avaialble.
Recent comparisons of file formats clearly revealed (to me) WAV the superior format.
Onkyo Music rep. suggested I find/ use a program to convert the FLAC (using format of choice) to WAV ? Knowing nothing about how this works, or more importantly if going from FLAC 'container' to WAV can even be faithfully (bit-for-bit) accomplished, I know not.
Anyone out there with answers ?
Thanks,
pj
Huge posted:I have one recording that apparently has a background hiss. Except it isn't: It's the sound of a rain shower falling outside the hall during the recording.
Do you remove that part of the signal?
I have two classical recordings done I. kingsway Hall in London, and the rumble of passing tube trains is definitely noise, but also definitely part of the ambiance, and it would take away the immediacy of the recordings to remove the sound.
Huge posted:It's no different, but they only claimed that the FLAC part of the process is lossless.
The whole process is still lossy. Using that whole process to try to prove anything about FLAC is utterly irrelevant.
The losses involved in removing the "noise" invalidate any conclusion form comparison of the result of the subsequent FLAC encoded data to the original LPCM data. To make any such comparison is fundamentally flawed even in principle never mind in execution.
The data compression in FLAC is functionally equivalent to the data compression of a ZIP file, but optimised for music. If you compress the data into a FLAC file then decompress the data, the data that result are EXACTLY the same as you put into the FLAC file in the first place. The presence or absence of noise makes no difference to that. However if you add a pre-step of removing the noise you're also removing part of the signal which you can NEVER recover - and that makes your whole process lossy.
If you remove the noise you invalidate the comparison..
If you leave the noise untouched, then there's no difference between the LPCM data, the data decoded from the WAVE file and the data decoded from the FLAC file.It really is that simple.
HUGE: And for that, I thank you. Nicely articulated.
pj
Can I just refocus for a moment, and query what this thread is now about?
Any talk of difference between different file formats - notably .wav and .flac is only relevant if neither deliberately modifies the sound in any wY. My understanding and experience of normal .flac, e.g. as transcoded by dBPoweramp, is that it does not remove noise, and is indeed lossless - and that can be verified, audibly by transcoding to fav then back to wav, and, I am sure though never tried, by analysis of the data.
a variant of flac that removes noise is a different beast entirely,
Innocent Bystander posted:Huge posted:I have one recording that apparently has a background hiss. Except it isn't: It's the sound of a rain shower falling outside the hall during the recording.
Do you remove that part of the signal?
I have two classical recordings done I. kingsway Hall in London, and the rumble of passing tube trains is definitely noise, but also definitely part of the ambiance, and it would take away the immediacy of the recordings to remove the sound.
IB: Understood. And agreed. If it was (as was of course) recorded as such, it must remain.
Perhaps if one considers ultrasonic noise and its removal if harmful to the end-result; music conveyance, this may be well worth the effort. If it is a"maybe", "possibly" "more harm than good" toss-up, it should remain.
It surprises me that (since you've touched upon acoustic ambiance) that more concern doesn't reside in the crucial LF spectra of music/venue acoustics; for, it is here, in this critical range that a wealth of musical detail resides -and that far more effort to ensure LF transparency is not often undertaken or discussed. (Nothing to do with our current discussion -directly anyway)
pj
Innocent Bystander posted:Can I just refocus for a moment, and query what this thread is now about?
Any talk of difference between different file formats - notably .wav and .flac is only relevant if neither deliberately modifies the sound in any wY. My understanding and experience of normal .flac, e.g. as transcoded by dBPoweramp, is that it does not remove noise, and is indeed lossless - and that can be verified, audibly by transcoding to fav then back to wav, and, I am sure though never tried, by analysis of the data.
a variant of flac that removes noise is a different beast entirely,
IB: Excellent. Great "summary".
"Thread about ...? "
All answered now, in large part to your (and H's) efforts. No doubt it drifted a bit but all relevant -to my mind.
Thank you.
pj
allhifi posted:Huge posted:allhifi posted:...
Flac is lossless.
Remove noise AND encode as FLAC is NOT lossless.
The action of removing the noise is a lossy transformation. Are you kidding me ?
- No I'm not kidding you: Removing noise IS a lossy transformation.I'm no Einstein, nor am I HUGE, but unless there is some data buried within the noise (previously unexpected), this seems reasonable. Otherwise, how in the world can noise removal (of a music data stream) be considered "lossy"?
It is not a matter of anything being considered, removing noise is lossy, period. This is true in general. It is actually not difficult to understand why it is so.
You only have to understand what it means for a transformation to be lossless or, in other words, reversible. What do you think this means?
The idea is very simple: a trasformation T (of, say, signals) is said to be lossless (reversible) iff there exists an inverse transformation, say T', such that T'(T(s)) = s for every signal s. This is a general notion and nothing specific of audio signals. But it applies to audio signals, of course. The crucial point here is that an inverse transformation T' has to exist for every signal s, not just for certain signals.
From this notion of losslessness, it directly follows that a T that removes noise cannot be reversible. The argument is straightforward: take a signal s that consists of only noise. Then, by definition of T, T(s) will be the zero signal: applying T to s removes the whole signal. Now, there is no transformation that can reconstruct an arbitrary (noisy) signal from the empty signal. Thus, T has no inverse. Thus, it cannot be lossless.
There is really nothing misterious or complicated in these notions once you have understood what they mean. There is plenty of examples of lossless transformations between data formats (zip and unzip, just to mention a very much used one) and of processes that are nearly reversible in the physical world. Think, for instance, to a spring: once you release the load, it goes back to its initial position.
You have received a lot of good answers to the questions that you have raised in this thread, among others by IB, Huge, SIS and many others. Try to take a break and thing about what they have been trying to help you understand.
nbpf, HUGE: Collectively speaking, bear in mind that (largely thanks to your efforts/remarks) it must be crucially respected that any "tiny" signal variance (particularly evident and concerning with compressions techniques, lossless or lossy) the opportunity for signal deviances (or manipulation) when encoding can result in sound quality observation distinctions upon playback. It wold be foolish to believe otherwise
From what has been discussed, emphasis shifted to the technical specification of bit-for-bit accuracy including even the delicate issue regarding "noise" however faint (if removed/altered, automatically implies a "lossy" format.
And that serves as an appropriate segue to the entire purpose of my original (and subsequent) queries, namely ; distinctions in sound quality via the encoding process (using FLAC) can understandably result when evaluating success during playback.
Regarding lossless compression formats (remaining with FLAC) I believe it was the chaps at Xivero that pointed out that every new specification yields new insights/understandings rendering previous versions shortcomings. It stands to reason that sound quality distinctions are a distinct possibility. No ?
A visit to xiph.org/flac revealed that since FLAC's inception (December 23, 2000) there have been twenty-one revisions to date. And not one of those revisions could account for SQ variations ?
Consider that I've been copying my CD's to computer (using WAVE & FLAC file formats) the past few weeks, I can't imagine that computer background operations, power supply fluctuations/noise and/or AC-power-line quality feeding the entire "system" would have no impact upon the proceedings.
Not to mention the FLAC spec. one is using. Similarly, newish 'Streaming' services (and audiophile software packages) looking for an edge in offering the best (or most distinctive) sound quality do not employ varying levels of signal manipulation in effort for increased sales/market penetration? In fact, how is it that competitors (and listener's) routinely discuss SQ distinctions of their platforms? Even if they do not (mess with signal), to think one receives a pristine unaltered signal once it arrives at your home (let alone DAC) is simply hard to digest. Yes, I'm aware that a perfect signal/file is (likely) claimed.
I will continue to search for answers that can explain such phenomena I believe exists. To think none do (exist), is rewinding the clock a bit too far back.
Were we not assured of the CD-format's proven superiority back in 1983 ? Precision data transfer was claimed -in fact existed back then, did it not ?
Did you nbpg/HUGE marvel at this then new technology ? Be honest.
pj
allhifi posted:nbpf, HUGE: Collectively speaking, bear in mind that (largely thanks to your efforts/remarks) it must be crucially respected that any "tiny" signal variance (particularly evident and concerning with compressions techniques, lossless or lossy) the opportunity for signal deviances (or manipulation) when encoding can result in sound quality observation distinctions upon playback. It wold be foolish to believe otherwise
From what has been discussed, emphasis shifted to the technical specification of bit-for-bit accuracy including even the delicate issue regarding "noise" however faint (if removed/altered, automatically implies a "lossy" format.
And that serves as an appropriate segue to the entire purpose of my original (and subsequent) queries, namely ; distinctions in sound quality via the encoding process (using FLAC) can understandably result when evaluating success during playback.
Regarding lossless compression formats (remaining with FLAC) I believe it was the chaps at Xivero that pointed out that every new specification yields new insights/understandings rendering previous versions shortcomings. It stands to reason that sound quality distinctions are a distinct possibility. No ?
A visit to xiph.org/flac revealed that since FLAC's inception (December 23, 2000) there have been twenty-one revisions to date. And not one of those revisions could account for SQ variations ?
Consider that I've been copying my CD's to computer (using WAVE & FLAC file formats) the past few weeks, I can't imagine that computer background operations, power supply fluctuations/noise and/or AC-power-line quality feeding the entire "system" would have no impact upon the proceedings.
Not to mention the FLAC spec. one is using. Similarly, newish 'Streaming' services (and audiophile software packages) looking for an edge in offering the best (or most distinctive) sound quality do not employ varying levels of signal manipulation in effort for increased sales/market penetration? In fact, how is it that competitors (and listener's) routinely discuss SQ distinctions of their platforms? Even if they do not (mess with signal), to think one receives a pristine unaltered signal once it arrives at your home (let alone DAC) is simply hard to digest. Yes, I'm aware that a perfect signal/file is (likely) claimed.
I will continue to search for answers that can explain such phenomena I believe exists. To think none do (exist), is rewinding the clock a bit too far back.
Were we not assured of the CD-format's proven superiority back in 1983 ? Precision data transfer was claimed -in fact existed back then, did it not ?
Did you nbpg/HUGE marvel at this then new technology ? Be honest.
pj
To be honest, I do not understand what you are talking about. I have tried to explain why a transformation that removes noise cannot be lossless. That's all. I hope that others can provide better explanations or that you'll come up with more satisfying answers to the questions that you are raising and that I do not understand. Take care, nbpf
Hi PJ
I'm not sure I understand your last post, so please excuse if I misinterpreted anything.
allhifi posted:nbpf, HUGE: Collectively speaking, bear in mind that (largely thanks to your efforts/remarks) it must be crucially respected that any "tiny" signal variance (particularly evident and concerning with compressions techniques, lossless or lossy) the opportunity for signal deviances (or manipulation) when encoding can result in sound quality observation distinctions upon playback. It wold be foolish to believe otherwise
From what has been discussed, emphasis shifted to the technical specification of bit-for-bit accuracy including even the delicate issue regarding "noise" however faint (if removed/altered, automatically implies a "lossy" format.
...
Indeed, at this stage we're talking solely about the digital domain, and specifically about the encode / decode cycle. In the case of WAVE and FLAC you always get back exactly what you put in (and this hasn't changed with any of the revisions to either specification).
allhifi posted:...And that serves as an appropriate segue to the entire purpose of my original (and subsequent) queries, namely ; distinctions in sound quality via the encoding process (using FLAC) can understandably result when evaluating success during playback.
...
Playback includes factors that can cause differences in sound that are dependant on the playback equipment and have nothing specifically to do with the encoding; furthermore these effects aren't reproducible between different types of playback equipment. This is why people transcode digital streams to WAVE format (i.e. LPCM), to reduce the effect of having other types of playback stream inside their player, as WAVE is the simplest format for the player to use to generate an electrical representation of the sound.
allhifi posted:...Regarding lossless compression formats (remaining with FLAC) I believe it was the chaps at Xivero that pointed out that every new specification yields new insights/understandings rendering previous versions shortcomings. It stands to reason that sound quality distinctions are a distinct possibility. No ?
A visit to xiph.org/flac revealed that since FLAC's inception (December 23, 2000) there have been twenty-one revisions to date. And not one of those revisions could account for SQ variations ?
...
ALL versions of the specifications for FLAC - absolutely all - guarantee that the data that you get back out are exactly the same as the data that you put in. The differences in the encoding only affect the amount of computing power required to encode and decode the data or change the allowable metadata. They don't change the data itself.
As there are no changes to the data there are no changes to the sound quality between these versions due to the mathematics of the encoding and decoding. The only changes would be in playback equipment caused by changes in the computing power needed to decode the data and the effect that this computing power has on the rest of the playback circuitry (the operation of the computer decoding the FLAC stream can interfere with the DAC and other analogue circuitry).
allhifi posted:...Consider that I've been copying my CD's to computer (using WAVE & FLAC file formats) the past few weeks, I can't imagine that computer background operations, power supply fluctuations/noise and/or AC-power-line quality feeding the entire "system" would have no impact upon the proceedings.
...
Indeed it has no impact, the data in the file are completely determined mathematically and are completely unaffected by other operations of the computer etc. (if this were not true then applications like Excel or your on-line banking application would routinely make mathematical errors!).
allhifi posted:...Not to mention the FLAC spec. one is using. Similarly, newish 'Streaming' services (and audiophile software packages) looking for an edge in offering the best (or most distinctive) sound quality do not employ varying levels of signal manipulation in effort for increased sales/market penetration? In fact, how is it that competitors (and listener's) routinely discuss SQ distinctions of their platforms? Even if they do not (mess with signal), to think one receives a pristine unaltered signal once it arrives at your home (let alone DAC) is simply hard to digest. Yes, I'm aware that a perfect signal/file is (likely) claimed.
I will continue to search for answers that can explain such phenomena I believe exists. To think none do (exist), is rewinding the clock a bit too far back.
...
I'm not at all sure what you mean here, but one observation.
When the data are fed across the internet the data don't arrive in an orderly fashion making it easy for the media player they arrive in clumps, and sometimes out of sequence. This requires the player's computer to put more computing power into sorting it all out, so it can pass the data to the DAC in an orderly manner. Again this extra computing power needed can cause interference in the analogue side of the media player, leading to degraded sound quality.
allhifi posted:...Were we not assured of the CD-format's proven superiority back in 1983 ? Precision data transfer was claimed -in fact existed back then, did it not ?
Did you nbpg/HUGE marvel at this then new technology ? Be honest.
pj
I looked at it, realised that the 'perfect sound' was almost possible, but not quite. I looked at the practical implementations of the technology and realised where they fell short of theory. I then designed and built my own amplifier to reduce the degrading effect of the limitations of technology in use at that time. I achieved a sound quality that was a lot better than most CD replay systems of the time.
No I didn't marvel at the technology - I fixed it's limitations instead!
Hi pj,
Following this thread it's clear you like to shake-up things. Bringing an avalanche of questions and doubting most of the shared knowledge of (at least for me) high appreciated fellow forum members.
Old saying is: "the more you know, the less you understand".
Got the impression you don't accept the knowledge so you can convince yourself that you still understand.
Hope this helps.
I will continue to search for answers that can explain such phenomena I believe exists. To think none do (exist), is rewinding the clock a bit too far back.
Why do you believe these phenomena exist? It comes across a bit like paranoia, apparently started by your hearing differences between playing .flac and .wav in your system, though you say that you've accepted the reasons for that. (Incidentally, have you yet tried the convert and convert back test and then listen for differences between the original and recreated .wav files?)
Can anyone explain what we are talking about now and what particular phenomenon is being referred to? Clearly nothing about WAV or FLAC encoding methods... perhaps this has moved from technical to some metaphysical/spiritual concept? or I might just be being slow... thanks
Well I know what I'm talking about...
WAVE and FLAC contain the same data after the decoding - no difference there.
However...
Wave (well LPCM anyway)... Low computing requirement for decoding - less interference transmitted through the PSU and directly coupled into the analogue circuitry.
FLAC - Higher computing requirement for decoding - more interference transmitted through the PSU and directly coupled into the analogue circuitry.
I'm glad it's the same for you Simon, I gave up a few days ago. I was considering applied transcendental idealism as a means of understanding this higher level of logic.
Simon-in-Suffolk posted:Can anyone explain what we are talking about now and what particular phenomenon is being referred to? Clearly nothing about WAV or FLAC encoding methods... perhaps this has moved from technical to some metaphysical/spiritual concept? or I might just be being slow... thanks
I cannot. I have just tried to explain why a transformation that removes noise cannot be lossless. Perhaps it was a bad explanation. Perhaps it was wrong. Or it was Huge's fault. I do not know. But we seem to have beamed Allhifi into a metaphysical/spiritual territory I feel uncomfortable with. Hope he will find his way back. I'm going to bed now. Best, nbpf
Mike-B posted:I'm glad it's the same for you Simon, I gave up a few days ago. I was considering applied transcendental idealism as a means of understanding this higher level of logic.
I have found red wine and grappa to be more effective in dealing with certain kinds of logic. Giving up is sometimes an act of wisdom, I guess.
nbpf posted:allhifi posted:nbpf, HUGE: Collectively speaking, bear in mind that (largely thanks to your efforts/remarks) it must be crucially respected that any "tiny" signal variance (particularly evident and concerning with compressions techniques, lossless or lossy) the opportunity for signal deviances (or manipulation) when encoding can result in sound quality observation distinctions upon playback. It wold be foolish to believe otherwise
From what has been discussed, emphasis shifted to the technical specification of bit-for-bit accuracy including even the delicate issue regarding "noise" however faint (if removed/altered, automatically implies a "lossy" format.
And that serves as an appropriate segue to the entire purpose of my original (and subsequent) queries, namely ; distinctions in sound quality via the encoding process (using FLAC) can understandably result when evaluating success during playback.
Regarding lossless compression formats (remaining with FLAC) I believe it was the chaps at Xivero that pointed out that every new specification yields new insights/understandings rendering previous versions shortcomings. It stands to reason that sound quality distinctions are a distinct possibility. No ?
A visit to xiph.org/flac revealed that since FLAC's inception (December 23, 2000) there have been twenty-one revisions to date. And not one of those revisions could account for SQ variations ?
Consider that I've been copying my CD's to computer (using WAVE & FLAC file formats) the past few weeks, I can't imagine that computer background operations, power supply fluctuations/noise and/or AC-power-line quality feeding the entire "system" would have no impact upon the proceedings.
Not to mention the FLAC spec. one is using. Similarly, newish 'Streaming' services (and audiophile software packages) looking for an edge in offering the best (or most distinctive) sound quality do not employ varying levels of signal manipulation in effort for increased sales/market penetration? In fact, how is it that competitors (and listener's) routinely discuss SQ distinctions of their platforms? Even if they do not (mess with signal), to think one receives a pristine unaltered signal once it arrives at your home (let alone DAC) is simply hard to digest. Yes, I'm aware that a perfect signal/file is (likely) claimed.
I will continue to search for answers that can explain such phenomena I believe exists. To think none do (exist), is rewinding the clock a bit too far back.
Were we not assured of the CD-format's proven superiority back in 1983 ? Precision data transfer was claimed -in fact existed back then, did it not ?
Did you nbpg/HUGE marvel at this then new technology ? Be honest.
pj
To be honest, I do not understand what you are talking about. I have tried to explain why a transformation that removes noise cannot be lossless. That's all. I hope that others can provide better explanations or that you'll come up with more satisfying answers to the questions that you are raising and that I do not understand. Take care, nbpf
Hi: You said: " ... I have tried to explain why a transformation that removes noise cannot be lossless"
(I truly understand. Nor argument. Thank you.)
In a nutshell, my "argument" is that seemingly innocuous details (whether during encoding, playback), adding or subtracting noise OR, this-that-and-other, there can be an accompanying change in subjective impressions.
nbpf, HUGE: Please answer the following: Did you marvel at the sound quality of the compact disc when introduced in 1982 -or indeed throughout the 1980's ?????
You may wish to reign-in the arrogant-leaning remarks such as "What don't you understand", "Trying to explain", "Some don't get it", along with the feeble attempts at sarcastic humor.
You know how to determine if one is both (mathematically) sharp but also really smart ?
Right then, I offer you the following:
" ... And like Rob Watts of Chord said in a Head-Fi forum interview not long ago, “My mantra is ‘You know nothing Jon Snow…’ and that is to remind me that there are very real limits to what I understand, and assumptions must be constantly tested with listening tests. Very big progress can be made by going down avenues that at first sight seem incapable of changing sound quality.”
That is so brilliant, the last part in particular, bears repeating: " Very big progress can be made by going down avenues that at first sight seem incapable of changing sound quality.”
So, big-shots here on Naim forums, really try to comprehend or at the very least show some humility.
pj
allhifi posted:<snip>nbpf, HUGE: Please answer the following: Did you marvel at the sound quality of the compact disc when introduced in 1982 -or indeed throughout the 1980's ?????
<snip>
I did answer your question.
Copied from my previous post...
allhifi posted:...Were we not assured of the CD-format's proven superiority back in 1983 ? Precision data transfer was claimed -in fact existed back then, did it not ?
Did you nbpg/HUGE marvel at this then new technology ? Be honest.
pj
I looked at it, realised that the 'perfect sound' was almost possible, but not quite. I looked at the practical implementations of the technology and realised where they fell short of theory. I then designed and built my own amplifier to reduce the degrading effect of the limitations of technology in use at that time. I achieved a sound quality that was a lot better than most CD replay systems of the time.
No I didn't marvel at the technology - I fixed it's limitations instead!
allhifi posted:<snip>" ... And like Rob Watts of Chord said in a Head-Fi forum interview not long ago, “My mantra is ‘You know nothing Jon Snow…’ and that is to remind me that there are very real limits to what I understand, and assumptions must be constantly tested with listening tests. Very big progress can be made by going down avenues that at first sight seem incapable of changing sound quality.”
That is so brilliant, the last part in particular, bears repeating: " Very big progress can be made by going down avenues that at first sight seem incapable of changing sound quality.”
So, big-shots here on Naim forums, really try to comprehend or at the very least show some humility.
pj
I'll give you another quote...
"I cannae change the laws of physics!" - Montgomery Scott.
It applies equally to mathematics and to entropy.
I’m not sure adults generally say ‘very big progress’. You’d surely expect the godlike genius who is Rob Watts to say ‘great progress’.
Huge posted:allhifi posted:<snip>nbpf, HUGE: Please answer the following: Did you marvel at the sound quality of the compact disc when introduced in 1982 -or indeed throughout the 1980's ?????
<snip>I did answer your question.
Copied from my previous post...
allhifi posted:...Were we not assured of the CD-format's proven superiority back in 1983 ? Precision data transfer was claimed -in fact existed back then, did it not ?
Did you nbpg/HUGE marvel at this then new technology ? Be honest.
pj
I looked at it, realised that the 'perfect sound' was almost possible, but not quite. I looked at the practical implementations of the technology and realised where they fell short of theory. I then designed and built my own amplifier to reduce the degrading effect of the limitations of technology in use at that time. I achieved a sound quality that was a lot better than most CD replay systems of the time.
No I didn't marvel at the technology - I fixed it's limitations instead!
'Huge': Your reply/disclosure revealed a great deal.
In fact, it deserves further unpacking:
1) "I looked at the practical implementations of the technology and realised where they fell short of theory". ( In-a-nutshell -what exactly did you realize/discover? )
2) "I then designed and built my own amplifier to reduce the degrading effect of the limitations of technology in use at that time." (What did you do/change with existing amplifier design ?)
3) " I achieved a sound quality that was a lot better than most CD replay systems of the time." (Was the bit-for-bit perfect signal/file -as represented by the Compact Disc- not to your liking then ?)
pj
Huge posted:allhifi posted:<snip>" ... And like Rob Watts of Chord said in a Head-Fi forum interview not long ago, “My mantra is ‘You know nothing Jon Snow…’ and that is to remind me that there are very real limits to what I understand, and assumptions must be constantly tested with listening tests. Very big progress can be made by going down avenues that at first sight seem incapable of changing sound quality.”
That is so brilliant, the last part in particular, bears repeating: " Very big progress can be made by going down avenues that at first sight seem incapable of changing sound quality.”
So, big-shots here on Naim forums, really try to comprehend or at the very least show some humility.
pj
I'll give you another quote...
"I cannae change the laws of physics!" - Montgomery Scott.
It applies equally to mathematics and to entropy.
Answer my questions, HUGE. (I'm confident Naim readers are also interested)
pj
Hungryhalibut posted:I’m not sure adults generally say ‘very big progress’. You’d surely expect the godlike genius who is Rob Watts to say ‘great progress’.
HH: It's his humility (sensibility) that stands out the most -although his work with digital audio remains equally impressive. The 'god-like' status (you) referenced also speaks volumes ...
pj
Bear in mind that this applies to the implementation of CD replay in the 1980s, I didn't do anything that would alter the theoretical principles of operation - they were good enough already...
1) The use of digital filtration as part of the DAC process was fairly rudimentary and combined with relatively limited analogue filtration was allowing a lot of energy to be retained in the ultrasonic region. This is an implementation issue not a fundamental issue of the theory.
2) I changed the amp design to prevent the ultrasonic spuriae for excessively influencing the driver transistors. This reduced IMD and TID, and prevented the driver transistors from entering a transitory latch up state. This gives a more stable condition for the output pair. This, in turn gives more stable conditions to the -ve input of the long tailed pair and ensures that there was less reliance on the feedback loop to ameliorate these distortions. I modelled these changes to ensure that the Nyquist margin was maintained. (Well, you did ask, so I hope you understand power amp design sufficiently.)
3) I didn't change anything on the digital side as it wasn't necessary. With a true (CRC checked) read of the data, or even a C1 error read, the Reed-Solomon reconstruction of the data is bit perfect - there's nothing to improve. (Note that the data on a CD are NOT written as simple LPCM values, they are Reed-Solomon encoded before being written to the CD and decoded by the player to reconstitute the LPCM values before these are committed to the DAC. This is a lossless mathematical process, and that mathematical process is, of itself, not open to improvement.)
allhifi posted:Huge posted:allhifi posted:<snip>" ... And like Rob Watts of Chord said in a Head-Fi forum interview not long ago, “My mantra is ‘You know nothing Jon Snow…’ and that is to remind me that there are very real limits to what I understand, and assumptions must be constantly tested with listening tests. Very big progress can be made by going down avenues that at first sight seem incapable of changing sound quality.”
That is so brilliant, the last part in particular, bears repeating: " Very big progress can be made by going down avenues that at first sight seem incapable of changing sound quality.”
So, big-shots here on Naim forums, really try to comprehend or at the very least show some humility.
pj
I'll give you another quote...
"I cannae change the laws of physics!" - Montgomery Scott.
It applies equally to mathematics and to entropy.
Answer my questions, HUGE. (I'm confident Naim readers are also interested)
pj
There wasn't a question there and I'd already answered the previous question.
I've answered the follow on question as well now (above).
Is this helping you with understanding the difference between FLAC encoding in FLAC files and LPCM encoding in WAVE files?