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High Resolution Audio?

Calexico

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Well good night. 32 bit 768khz is purely marketing. It's not real values. It's like having a 800*600 vidéoprojector that can accept 4k movies.
 

solderdude

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32 bit 768khz is purely marketing. It's not real values.
For audio reproduction (playback) you are (finally) half correct about something ...
The bottom 12 bits or so will drown in noise for sure when converted to analog.
A 300kHz audio bandwidth will be a real value but 'somewhat' overkill for home entertainment.

I would not be surprised if 'golden eared' folks will step up an claim audible superiority over say 384/24 ... because of the transients for instance :rolleyes:
 

eliash

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I'm not pushing hires. However the reason it isn't needed is not because there are no DACs that can perform with those formats.

And yes, I most definitely would say 32 bit 784 khz is pure marketing. There is an edge case to be made for 96 khz. I don't see one at all for more than that for music use. 96/16 with noise shaped dither would give you all you can make use of down to about -120 db.
After the last days of the discussion, this would be my best guess as well. From my technical perspective all that discussion wouldn´t have come up, if Philips/Sony would have waited a bit and moved into the market with 64KHz/18bits...
 

Krunok

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I'm not pushing hires. However the reason it isn't needed is not because there are no DACs that can perform with those formats.

And yes, I most definitely would say 32 bit 784 khz is pure marketing. There is an edge case to be made for 96 khz. I don't see one at all for more than that for music use. 96/16 with noise shaped dither would give you all you can make use of down to about -120 db.
I would say judging from the music I'm buying online that the most popular format in last 2 years after 44.1/6 is 48/24 followed by 96/24.
 

eliash

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I had the same issue. I used to put two in series. One position just connected the second one straight thru. So that gave me 23 positions.

I later snagged some milspec silver contact 36 position switches at a ham show. I never used them.

I ended up basically putting the resistors in a ladder configuration similar to a R2R ladder DAC. I only used 7. So I had 128 positions. I put toggle switches in and you could adjust with excellent precision with only 7 switches. It was surprising how quickly the settings became second nature though at first it seemed chaotic.
Great idea to stack the switches, sometimes it is good to be forced away from common practice...on the other hand, after 30y using an otherwise really great Yamaha amp without remote volume control, it was clear to me, that this was a must have for a new amp.
So I invested in one with a 4 track motor pot, which can be even engaged in 40 steps up and down again with a Pronto remote control (they must have foreseen this in their controller FW long time ago).
A neighbour has a Schäfer Emitter amp, this has some kind of relais matrix (clicking noise) and is remote capable too. Lately I used Vactrol replicas from China to black-out open input lines on demand, this could be eventually a noiseless switch alternative to control a resistor network...
 

maty

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solderdude

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You can clearly hear the quality difference between old fashioned mpeg, red book, flac, WAV and dsd. Clearly...
Did you mean:
I can clearly hear the quality difference between old fashioned mpeg, red book, flac, WAV and dsd at least when I know WHAT is playing and the recording is not exactly the same and level matched.
 

maty

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It should be evident that the level must be the same, at least in my case. It is the first thing you think! The first stranger is me but I can not deny the evidence. In his day I had to study Nyquist deeply. Therefore my conclusion is that one thing is the theory and another is its practical implementation.
 

Calexico

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For audio reproduction (playback) you are (finally) half correct about something ...
The bottom 12 bits or so will drown in noise for sure when converted to analog.
A 300kHz audio bandwidth will be a real value but 'somewhat' overkill for home entertainment.

I would not be surprised if 'golden eared' folks will step up an claim audible superiority over say 384/24 ... because of the transients for instance :rolleyes:
Are there tests to compare transients of dacs?
How is it possible to know that the transient of the records in dacs are respected. Is it hearable in timbre?
I guess that was the goal of mqa.
 

eliash

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One last reply for today, have a look at this from your recommended paper, which I had in mind in the above. The oversampling math seems to reconstruct the clipped original signal and results in a "true peak" reading...anyway tomorrow I read that again entirely and now I enjoy the rest of the "Tatort" TV movie...

View attachment 27435
Aha!...after reading some of the above linked "Recommendation ITU-R BS.1770-4", especially the latter part "Appendix 1 to Annex 2 (informative) ", starting from page 20pdf. This is well eleborated and easy to understand.
I noticed that this really concentrates on intersample peaking.
This was not in my primary focus in my intended analog application, so I was purely focused on the above picture. I think this has accidently conveyed a view with several samples at max. level to me, because I understood that regular peak meters are capable on counting these consecutive samples, and based on threshold number, they will issue a peak alarm.
This is exceeded by this TP-meter´s capabilities (plus other nice measurement features), which is here connected behind the DAC, on the analog line, driving the analog amp, because I use it similarly for the analog Vinyl.
(Why?...For me this is somehow a similar urge, like checking before what I eat...here of course during consumption...)

In general, the applied use-case for the TP-value only, is to judge whether heavy digital clipping or analog distortion is relevant on the analog line. From what I have seen, there are many digital tracks present causing above 0dBfs readings, but in the range below +1dBfs (In terms of distortion to expect, Vinyl is more difficult to judge, but TP gives quite a reasonable view on the level, when stylus tracking loss becomes critical).
This kind of TP reading is OK for me, since I can do (with limited accuracy) cherry picking on different tracks or album versions and have a general view on track properties...

- This raises finally the question, whether intersampling peaks are measureable in such a setup at all, since the DAC did the resampling signal restoration before, my ADC driving the TP-meter running at 96K (well, the DAC-filter roll-off is somewhere around 85KHz) - does anybody have an opinion on that???


I have to try the "killer" 1/4 sampling rate tone....
 
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solderdude

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Are there tests to compare transients of dacs?
How is it possible to know that the transient of the records in dacs are respected. Is it hearable in timbre?
I guess that was the goal of mqa.
There are plots showing how DACs respond to illegal signals that do not exist in audio files.

I really recommend you analyze transients in music pieces and you will find the transients you hear as transients are spread out over many samples and thus well below Nyquist, even at 44/16 and don't have any risetimes anywhere near nyquist at all *.
DAC's have no trouble reproducing these 'transients' in music.
Do you have any evidence (other than anecdotal and sighted) pointing towards this ?

With the exception perhaps of Ray's spoon tapping and some castanets.
 
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Frank Dernie

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After the last days of the discussion, this would be my best guess as well. From my technical perspective all that discussion wouldn´t have come up, if Philips/Sony would have waited a bit and moved into the market with 64KHz/18bits...
I’m afraid I doubt it.
The same type of person would find something to complain about IME.
 

Calexico

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There are plots showing how DACs respond to illegal signals that do not exist in audio files.

I really recommend you analyze transients in music pieces and you will find the transients you hear as transients are spread out over many samples and thus well below Nyquist, even at 44/16 and don't have any risetimes anywhere near nyquist at all *.
DAC's have no trouble reproducing these 'transients' in music.
Do you have any evidence (other than anecdotal and sighted) pointing towards this ?

With the exception perhaps of Ray's spoon tapping and some castanets.
No idea. Just mqa was made for having same filter as adc and keep the transient unchanged. Don't know if it makes any difference.
 

Blumlein 88

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No idea. Just mqa was made for having same filter as adc and keep the transient unchanged. Don't know if it makes any difference.
Did you know that PCM was made to have the same filter on both ends too. And it really works well. Then various people starting using various other filters on the DAC end to change the sound or try to, and saying it was better. Mostly it is different, and not quite as good, or accurate etc.

I've posted some 176 khz sampled cymbal crashes recorded with wide bandwidth microphones, and like you are being told, something like that which you think is a steep transient isn't so steep. Well within CD to record. It builds over several samples as the metal cymbal having been struck ramps up to a resonance, and then decays.
 

Krunok

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Did you know that PCM was made to have the same filter on both ends too. And it really works well. Then various people starting using various other filters on the DAC end to change the sound or try to, and saying it was better. Mostly it is different, and not quite as good, or accurate etc.

I've posted some 176 khz sampled cymbal crashes recorded with wide bandwidth microphones, and like you are being told, something like that which you think is a steep transient isn't so steep. Well within CD to record. It builds over several samples as the metal cymbal having been struck ramps up to a resonance, and then decays.
I'm sorry but I don't think you can kill a DAC with cymbals - only @RayDunzl demonstrated he can kill a DAC with a spoon. :D
 

Calexico

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Did you know that PCM was made to have the same filter on both ends too. And it really works well. Then various people starting using various other filters on the DAC end to change the sound or try to, and saying it was better. Mostly it is different, and not quite as good, or accurate etc.

I've posted some 176 khz sampled cymbal crashes recorded with wide bandwidth microphones, and like you are being told, something like that which you think is a steep transient isn't so steep. Well within CD to record. It builds over several samples as the metal cymbal having been struck ramps up to a resonance, and then decays.
Mqa claims that in old digital records adc had different filters. Then mqa say to the dac wich filter is adapted so that the dac use the same as the adc.
I agree that ideally dac should decode pcm to analog the same way that the adc encode analog in pcm.
Using different filter in adc and dac can lead to hearable differences you think?
Apodising filter claims that it adapts to the filter used on the adc.
 

FrantzM

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Bob Stuart is an authority, no doubt. When he speaks one would normally listen. The thing about MQA is that it seems to be a solution in search of a problem.
I have been in the IT business for a long time. I have seen 64 Kb/s CSU/DSU labelled as "High-Speed" ... SIXTY FOUR K-I-L-O_B-i-t-s per SECOND. Those were the days when something called a T-1 which at the torrid pace of 1.544 Mb/s was reserved to corporations at over $1,000.00/month... There was also a T-3 which was reserved for the very largest enterprises in the world at 45 Mb/s... well over $3,000.oo a month 20 years ago... We are not there now, no one would dare claim 3 Mb/s as "fast"... So what's the use for MQA when and where PCM Redbook is transparent and available? ... What does it bring that PCM doesn't? Less storage? Not really an issue in this world of 10 TB HDD @ $200... And when we factor that most people, cannot reliably distinguish 320 mp3 or whatever codec you care to name to CD? Now let's move to the audiophile who wants his files bit perfect ? He has Redbook or if he (mostly HE) fancies it ... He'd move to the so-called Hirez, those that do not require special hardware and software to process their files which I believe MQA does ... So the more one looks a MQA the less you understand its value proposition ... Perhaps the same fate as DVD-A?
 
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