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DAC types and their sonic signature

Xulonn

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I've noticed a strong correlation between people who own Bose and people who drive Volvos.
When I moved in with my late partner in 1996, she had a Bose cube/sub system driven by a decent Onkyo receiver. I quickly replaced it with a Bryston B60R integrated amp and a pair of Apogee Centaurus Ribbon monitors. Big improvement. We shared a love of classical music - especially Beethoven - and she approved of the upgrade.

Apogee Centaurus Ribbon Monitors - 2.jpg


She also drove a 1987 Volvo 245 station wagon that she had purchased new. When she passed away in 2005, I was 64 y/o and I sold my windsurfing/camping van and kept the Volvo - and drove it until moving to Panama in 2012. The automatic Volvo was gutless, and handled like sh!t until I put a set of used Volvo alloy wheels on it. That was the most incredible improvement in handling that I have experienced in an automobile - it went from gross, dangerous oversteer to neutral with no other changes. But it was still gutless!

Emily.jpg
 

pozz

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That's just my personal take on what is being said that's all.
If you read between the lines, that's essentially what's going on is it not?

BOSE "better sound through research"

Their tagline says it all really. Again, that's my personal opinion.

My father in law had a BOSE sound wave cd player for over 10 years and loved it.
It developed a fault and, with it being out of warranty, decided to take it apart to see if he could fix it (he's like that).
Anyway, he was shocked at what he saw inside.
Basically a small PCB with speaker wire going to the two tiny 2.5 inch drivers with an elaborate series of slats which directed the soundwaves (for want of a better word) which gave the illusion of good sound.

That's my point. An empty box with fancy trickery to fool the brain into thinking you're hearing good sound.

You're really not hearing good sound though are you.

That's my opinion anyway.
Although I don't like the sound of Bose products, I think here the more appropriate thing to say is that the company uses knowledge of acoustic principles better than most in the retail sphere. That sort of coupling of waveguides and drivers is very difficult to achieve.

Edit: Sorry, late to the game. I see all this has already been discussed above.
 

solderdude

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Simple digital filters introduce audible ringing. Why it doesn't show in those simple tests - I don't know.
Where is it written that 'simple digital filters' introduce audible ringing ?
Do more complicated filters not introduce audible ringing ?
What would you say are 'simple' filters and why are they 'simple' ?

why? One must really ask himself, do those guys know/understand something that I don't?
They probably do, doesn't justify their decisions which can be based on 'being different because of being different'

mind that some of best sigma-delta DAC designs paid lot of attention to filtering, and a simple brick wall filter was not the choice.
What is a 'simple brickwall filter' and why do you not see those as an option in DS designs ?
Would you not consider the fast/steep linear phase option a proper (and objectively optimal) reconstruction filter that shows best performance ?
 

JJB70

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I think that the Sony 1000XM3 is probably the best noise cancelling headphone there is just now but the Bose QC35 II is very close and depending on individual preferences some find the Bose more comfortable. Either way, whatever people think of Bose I do think that their noise cancelling headphones are superb.
 

solderdude

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He tested OS filterless DAC.
Its the words filterless and NOS that matter here not whether or not the DAC chip is capable of OS and using various filters.
It is a pretty good/accurate emulation of a typical NOS filterless R2R DAC but without the amplitude errors that plague R2R implementations.
 
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I see some argues with ringing so I'll explain how interpolation works.
Oversample = just adding more points to the file.
Interpolate = upsample = adding more points and applying a filter to avoid imaging

DAC manufacturers interpolate the PCM file up to 512 times or 1024 times. But they don't do it at single stage. First, they oversample the file up to about 4-16 times(and match every files to similar sampling rate) and apply good anti-imaging filter.
Red line: Original signal
Orange line: Imaged signal
2.PNG

Then, they apply simple interpolation filters with poor filters because there is enough room for filter to attenuate.
3.PNG

And this is the final result
4.PNG

But it would have been better with sharper filter
5.PNG

This is what so many audiophiles have fought of. DAC performance don't degrade so much with slow filter and there is no audible ringing issue with sharp filter. Frequency range can be converted to maximum steepness a wave can have. The wave won't ring if sufficient steepness to stop ringing is allowed. This is just like driving a car. A heavy car needs to turn widely and slowly.
5.PNG

An impulse signal with slow filters don't have so much ringing just because it contains higher frequency(In this case, its partial image of original file). Ringings are not natural waveform because nature is not frequency-limited. But our ears are frequency-limited and always hear ringings. In other words, even if your DSD256 high-res album is reproduced perfectly, your ears are not high-res and hear ringings generated by your ear itself.

Then, what is NOS dacs on the market? If you look at the waveform of the NOS dac, it will look like this.
6.PNG

The waveform of NOS dac is the one you can see at ladder dac with bypassed(or insufficient) low-pass filter. Actually, the NOS dac with commercial delta-sigma dac chip is not 'Non-Oversampled'. The 2nd stage interpolator and delta sigma modulator is impossible to bypass and no signal can be printed out without them. It is emulated through old interpolation technique called zero-order hold interpolation.
This is what the original PCM file is representing. It is made of several points indicating the level.
8.PNG

Now lets add some more points to it.
7.PNG

That's it. This will be put into 2nd stage interpolator and modulator.
In frequency domain, this can be achieved by simply oversampling the signal and applying a filter like this.
9.PNG

In short, if you apply a very very poor filter after oversampling, a nice stair-shaped wave is made.
Normal delta-sigma DAC
View attachment 29463
NOS emulating dac
10-1.PNG

Cirrus Logic patent
The result is massive amount of image that is very likely to cause distortion problem unlike slow filter. Although a strict brick-wall filter is not so necessary to real performance, using NOS filter will reduce its SINAD performance. But I'm not sure about audibility of distortion caused by NOS filter.
 

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Veri

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The result is massive amount of image that is very likely to cause distortion problem unlike slow filter. Although a strict brick-wall filter is not so necessary to real performance, using NOS filter will reduce its SINAD performance. But I'm not sure about audibility of distortion caused by NOS filter.
Images, ultrasonics, but most definitely there is the treble roll-off. Thankfully our ears are ignorant and the audible flaws are not that severe, even with NOS. Some even like its defective sound..
 

zalive

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Its the words filterless and NOS that matter here not whether or not the DAC chip is capable of OS and using various filters.
It is a pretty good/accurate emulation of a typical NOS filterless R2R DAC but without the amplitude errors that plague R2R implementations.
I don't find a single mention in Archimago's blog that it was without OS. He mentions 'digital filter off', 'NOS mode' and this:
as well as an OFF mode which results in removal of the oversampling filter and hence a "NOS" mode of operation.
If you remove OS filter it doesn't imply you removed the OS as well. Archimago never mentioned OS itself was removed.

Furthermore, as @hetzer explained, even if you switched off the oversampling from sigma-delta DAC, you will still have a form of oversampling because it's the way sigma-delta DA conversion functions in its meaningful implementation.

If you want a real NOS you need a R2R DAC.
 

zalive

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Images, ultrasonics, but most definitely there is the treble roll-off. Thankfully our ears are ignorant and the audible flaws are not that severe, even with NOS. Some even like its defective sound..
Of course, some even like sigma-delta defective sound too. It's incredible. Don't trust what you hear, instead trust those numbers from simple test which don't emulate music at all, then bias yourself with all those graphs to believe what you hear is top of the world. Self-hypnosis at max level. Well it's great if it works for one. Eventually having ears won't be necessary at all for some, looking at ones and zeroes will do.
 
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pkane

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Of course, some even like sigma-delta defective sound too. It's incredible. Don't trust what you hear, instead trust those numbers from simple test which don't emulate music at all, then bias yourself with all those graphs to believe what you hear is top of the world. Self-hypnosis at max level. Well it's great if it works for one. Eventually having ears won't be necessary at all for some, looking at ones and zeroes will do for some.
You do realize that there are tests that do use any piece of music you want, and that they largely confirm the results of the more simple tests, and that this agrees with theory and practice of audio engineering?

Occam’s razor would indicate that you should, instead, examine your assumptions as possibly faulty, as it’s much easier for the ear/brain to be deceived than it is for a mindless measurement instrument.
 

solderdude

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I don't find a single mention in Archimago's blog that it was without OS. He mentions 'digital filter off', 'NOS mode' and this:

If you remove OS filter it doesn't imply you removed the OS as well. Archimago never mentioned OS itself was removed.

Furthermore, as @hetzer explained, even if you switched off the oversampling from sigma-delta DAC, you will still have a form of oversampling because it's the way sigma-delta DA conversion functions in its meaningful implementation.

If you want a real NOS you need a R2R DAC.
You do not seem to understand how a DAC works, Hetzer tried to use graphics where I tried to use words.

The NOS mode in the UD501 emulates of the actual output a filterless R2R in NOS mode. In other words the stairsteps are shown.
You cannot switch off the DS part so also not the oversampling.
When the DAC chip is instructed to keep the sample value continuous for 1/44100 of a second it will just do that.
Just like a NOS R2R DAC chip does by nature.

I suggest you look into NOS mode of that chip and read Archimago's article more closely and the conclusions he draws.

If you want real filterless NOS DACs you don't need an R2R, you need your head examined or have to admit you don't want to hear what has actually been recorded and prefer a certain coloration.
NO filterless DAC has an accurate reproduction without it being fed well over 96kHz files or being fed computer upsampled files (with a proper steep filter).
Reproducing 44.1 and 48kHz files with a filterless NOS R2R DAC is NOT more accurate at all.
Reproducing 44.1 and 48kHz files with a properly filtered NOS R2R DAC is fine.
 

solderdude

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Of course, some even like sigma-delta defective sound too. It's incredible. Don't trust what you hear, instead trust those numbers from simple test which don't emulate music at all, then bias yourself with all those graphs to believe what you hear is top of the world. Self-hypnosis at max level. Well it's great if it works for one. Eventually having ears won't be necessary at all for some, looking at ones and zeroes will do.
The typical response of someone that trusts their ears but NOT under blind (not knowing) and level matched conditions.
The fact that they seem to loose their obvious ability seems so frightening that they refuse to test 'blind' and come up with the retardest explanations why blind tests and measurements are worthless.
The ears only seem trustworthy when one knows what is being listened to.... and engineers are stupid and have poor hearing and are biased... and they smell too.... and ....
 

zalive

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You do realize that there are tests that do use any piece of music you want, and that they largely confirm the results of the more simple tests, and that this agrees with theory and practice of audio engineering?

Occam’s razor would indicate that you should, instead, examine your assumptions as possibly faulty, as it’s much easier for the ear/brain to be deceived than it is for a mindless measurement instrument.
My ears aren't satisfied. I don't care for graphs, I care for my satisfaction, enjoyment of listening to the music.

I also have a Raspberry Pi + Hifiberry Dac+ Pro. It's a simple yet nice design and it sounds really great for its cost. But to be really satisfied with its sound I need a system with a treble roll off. I connected it to one such (system 2, actually at my parents home living room). Bookshelf speakers with a custom notch filter to tame its 11-12 khz hump plus a serial resistor on a tweeter (value tweaked to my listening liking) to tone down the treble in general. Works like a charm and I'm really satisfied with a sound, considering it's obvious limits. It's not completely neutral but it's live and it fulfills me. If I replace those speakers with ATC SCM19 v2 which are quite close to this neutral sound ideal, the result doesn't sound that well. You hear that distortion which accenuate the highs. Replace the Hifiberry with NOS AD1865 DAC and ATC's work like a charm (only with much more neutrality compared to the system described first, this is of course yet better sound).
 

zalive

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If you want real filterless NOS DACs you don't need an R2R, you need your head examined or have to admit you don't want to hear what has actually been recorded and prefer a certain coloration.
I use a filterless NOS DAC at my system 1. You should hear the sound, then judge how do you like it.
A trained audio professional thinks this DAC sounds neutral. He made one for himself.
But if you really prefer sigma-delta DAC sound, stick to those. Or if all sounds the same to you, stick to whatever you want.
I don't. If I preferred it at first place you would not see me write in this thread.

Did you do a blind test listening of the sample I put? It takes few minutes, just headphones, click and switch off the screen. Listen to it, then tell how you like the sound. Just preferrence.
 

solderdude

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My ears aren't satisfied. I don't care for graphs, I care for my satisfaction, enjoyment of listening to the music.
I am in complete agreement agreement. I look look at graphs to make a better educated guess about some parts of its performance and to see if there are no deal breakers.

My preference is of no importance.
What is being discussed here is whether or not a filterless NOS R2R DAC outputs the intended signal.
It does not. Any DS DAC is far more accurate.

Facts are: a filterless NOS R2R DAC cannot reproduce the recorded signal accurately as it does not comply to the theorem. Period.
It is not BETTER, the fact that some people like or prefer that sound is an entirely different thing.
 

pkane

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My ears aren't satisfied. I don't care for graphs, I care for my satisfaction, enjoyment of listening to the music.
So you don't care if there really is a difference, as long as you hear one. That's fine, but has nothing to do with science or engineering -- more with psychiatry. I can't hear what's in your head, so you sharing your audiophile experiences with me is meaningless: I'll hear something completely different from you with exactly the same equipment, since my imagination works differently.

You seem to think that all 'objective' types have no clue about what 'subjectivists' hear. Couldn't be possibly further from the truth. I bet you that a large percentage of ASR readership has gone through a subjectivist phase where they heard the same things you do. Until they questioned their assumptions and tried to validate them using controlled testing. I suggest you try it, too, no harm in doing so if you know that you're right?
 

zalive

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So you don't care if there really is a difference, as long as you hear one. That's fine, but has nothing to do with science or engineering -- more with psychiatry. I can't hear what's in your head, so you sharing your audiophile experiences with me is meaningless: I'll hear something completely different from you with exactly the same equipment, since my imagination works differently.

You seem to think that all 'objective' types have no clue about what 'subjectivists' hear. Couldn't be possibly further from the truth. I bet you that a large percentage of ASR readership has gone through a subjectivist phase where they heard the same things you do. Until they questioned their assumptions and tried to validate them using controlled testing. I suggest you try it, too, no harm in doing so if you know that you're right?
It's not about a difference, it's about taste, liking, preference.
There's no difference between objectivists, subjectivists or any other listener who would not subscribe exclusively or at all to either, in this regard.
We all have our personal taste.
And neither of us really knows whether this own personal taste is completely neutral.
In the end it's completely unimportant when it comes to enjoying the music.
Systems we listen to are never completely neutral as a whole, nor they can be in a realistic worls.
Recordings we listen to are never completely neutral nor they can be. Sometimes they try to emulate the live event, sometimes even not, just trying to appeal to the listeners with the sound.
In the end, preference will decide the choice.
If you look to graphs, then say well that's my preference, it's called a bias.
 
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