Yes. Who is able to ear -3 db or 20% of distortion at 20 kHz?
I you want to design a good DAC, don't waste your time with false problem. It is not above 10kHz that problem occurs.
When you put a scope on a NOS DAC, you see incredible signal! Worse than you can imagine in your nightmare! There is no relationship between what you see or measure and what your ear. What's important for you : scope, distortion, pass-band ripple or human earing?
I used a Audio Note NOS dac for years. Then I started messing with TDA1541 players and tube output stages, and it sounded sò much better!
At first I thought it was because I designed a superb tube stage, but after a while it occurred to me I was using OS.
To make it complete I converted a player to NOS, and I immediately recognized it, this was the typical NOS sound. I didn't use any filters there, as opposed to the Audio Note, but still..
OS sounds more lively, the stereo image is very clear an deep, NOS sounds dull and woolly. Sometimes I understand why some people call it 'more musical', but like it's been said before: only with certain music. I listen to rock mostly, and that's no NOS music 🙄
At first I thought it was because I designed a superb tube stage, but after a while it occurred to me I was using OS.
To make it complete I converted a player to NOS, and I immediately recognized it, this was the typical NOS sound. I didn't use any filters there, as opposed to the Audio Note, but still..
OS sounds more lively, the stereo image is very clear an deep, NOS sounds dull and woolly. Sometimes I understand why some people call it 'more musical', but like it's been said before: only with certain music. I listen to rock mostly, and that's no NOS music 🙄
A filter for each music
Hello Miniwatt,
[
...OS DAC for Rock and NOS DAC for Classical... 
]
The problem is (of course) not so simple, but what you say is totally true.
The global result depends on recording studio's works.
- When you have a flat recording, OS DAC adds some life (a bit), cancel defaults (a bit) and gives depth (a bit). With NOS, it still flat and dull. Good point for OS DAC.
- When you have a good recording, OS DAC cancels details (a bit) and provide unnatural (a bit) and foggy sound (a bit). NOS DAC seems more natural, detailed and less foggy. Good point for NOS DAC.
I remember a listening session, we could hear a flat and dull Dire Straits on OS DAC appearing juicy and not so bad with NOS DAC 😕
Hello Miniwatt,
Here is a very good remarks. Here is the reason why some people prefer NOS and other OS.
[
...OS DAC for Rock and NOS DAC for Classical... ]The problem is (of course) not so simple, but what you say is totally true.
The global result depends on recording studio's works.
- When you have a flat recording, OS DAC adds some life (a bit), cancel defaults (a bit) and gives depth (a bit). With NOS, it still flat and dull. Good point for OS DAC.
- When you have a good recording, OS DAC cancels details (a bit) and provide unnatural (a bit) and foggy sound (a bit). NOS DAC seems more natural, detailed and less foggy. Good point for NOS DAC.
I remember a listening session, we could hear a flat and dull Dire Straits on OS DAC appearing juicy and not so bad with NOS DAC 😕
That is what I have done many times with diffrent output stages.
Agree
I don't claim OS is all good but to me it's always a much less compromised, just sounds way better.
I also don't claim it is impossible to have good sounding NOS DAC. It probably is but I doubt this will be DIY home made DAC. I belive some Kondo, Zanden or other sophisticated NOS machines can sound fantastic.
I think it may have something to do with some people being more critical to hear some anomalies of some frequency band and some other less. Maybe some just hear the bad things in NOS other just don't hear, I don't know.
Bartek
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Funny thing is when I presented the diffrance OS vs NOS to my few quite advanced audiophile friends (TDA1541A DAC) they all preferred OS, mostly not even knowing what OS and NOS is.
Hello
The Intermodulation and product frequencies in the preamp and amp folowing a non-os Dac, and cause by the HF noise from the 44khz of the non filtered or just a bit filtered non-oversampling Dac are why this type of Dac are not very good with large orchestral music and cause fatigues with this type of music. Most of my friends say that NOS dac are good on jazz music or classical chamber music.
So a NOS dac need a analog brick wall filter but those type of filter cause too much phase shift, so we can only use a second or third order bessel filter and some of the HF noise from the 44khz will still there.
Bye
Gaetan
The Intermodulation and product frequencies in the preamp and amp folowing a non-os Dac, and cause by the HF noise from the 44khz of the non filtered or just a bit filtered non-oversampling Dac are why this type of Dac are not very good with large orchestral music and cause fatigues with this type of music. Most of my friends say that NOS dac are good on jazz music or classical chamber music.
So a NOS dac need a analog brick wall filter but those type of filter cause too much phase shift, so we can only use a second or third order bessel filter and some of the HF noise from the 44khz will still there.
Bye
Gaetan
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Try with a dem reclocked TDA1541A dac, you will see the difference in sound between OS and NOS.
it is simply a implementation of moving average filter, for 16/44,1 has almost no benefit from NOS but introduce new problems
no, OS has almost the same sensitive to jitter as NOS, for "white" jitter OS is less sensitive if DF has good stopband attenuation -100db or more
http://www.diyaudio.com/forums/digital-source/124069-nos-dac-ves-oversample-dac-3.html#post2017866 post 21
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Hello Nazar_lv
It's not a good point of view to think that upsampled data are outside the audio band.
Look at the joined diagram:
- dot in ... color are real samples recorded on CD,
- dot in ... color are 2x ovsl sample
Can you say me where are the samples recorded on CD. 🙄
OS is much jitter sensitive because each output sample contain same 'amount of jitter'. By increasing output sample you increase total amount of jitter. It's the problem number one in one-bit DAC where oversampling can reach 256x.
It's not a good point of view to think that upsampled data are outside the audio band.
Look at the joined diagram:
- dot in ... color are real samples recorded on CD,
- dot in ... color are 2x ovsl sample
Can you say me where are the samples recorded on CD. 🙄
Attachments
Hello Nazar_lv
Which new problems the shift-registers dac does introduce ?
Thank
Bye
Gaetan
no, it is simple audiophile idiotism🙂
When we increase sapling rate this will reduce the sample to sample amplitude difference and random jitter induced distortion will be less by oversampling factor, for sinosuidal jitter within baseband will be not rejected and will be the same as in NOS.
A 1bit DS modulator has a step size that is fullscale(0-5v PWM) thats why this DACs is very sensitive to jitter, if we use more output levels("multibit" or "multilevel" DS) and use discrete time filtering (SC filters or DCT (Direct Charge transfer) DAC) then jitter sensitivity will be less.
it is very simple explain becouse my english is not very good.
I dont understand you question
moving average filter is interesting only for 192khz sampling rate, for 44,1 he only do HF rollof, many DACs and logics introduce much more EMI and PCB design will be much harder and less optimal
So the poll is finished and the results are there for all to see!!
The OS people made a late surge - early on, the NOS option was wayyy ahead. Also its interesting to read the thread and the numerous comments on how at least some NOS dacs measure poorly, but still seem to be favoured by the majority.
Comments were made RE: poor execution of desisgns.... well I think its just as easy to make a poor OS DAC as a poor NOS DAC so bth kind cancel each other out there.
Those who favoured the NOS DACs all seemed to mention liquidity and analog nature of the sound, whereas those who preferred the OS route, seemed to mention precision of soundstage and clarity, superior detail retreival.
The one big unknown in all this of course is all the other listening equipment. I kinda believe that NOS sounds better in my system - my speakers are fostex full rangers that would naturally tend towards being a bit sharp when pushed - so naturally something smooth really helps there. If your speakers/ancillary equipment tends the other way, OS may sound better I suppose.
Interesting discussion though.....
Fran
The OS people made a late surge - early on, the NOS option was wayyy ahead. Also its interesting to read the thread and the numerous comments on how at least some NOS dacs measure poorly, but still seem to be favoured by the majority.
Comments were made RE: poor execution of desisgns.... well I think its just as easy to make a poor OS DAC as a poor NOS DAC so bth kind cancel each other out there.
Those who favoured the NOS DACs all seemed to mention liquidity and analog nature of the sound, whereas those who preferred the OS route, seemed to mention precision of soundstage and clarity, superior detail retreival.
The one big unknown in all this of course is all the other listening equipment. I kinda believe that NOS sounds better in my system - my speakers are fostex full rangers that would naturally tend towards being a bit sharp when pushed - so naturally something smooth really helps there. If your speakers/ancillary equipment tends the other way, OS may sound better I suppose.
Interesting discussion though.....
Fran
Is there a possibility that the generation that was born after the cd domainated the market perfer OS sound?
Like my childrens they have never listen to a record.
I like NOS because it sound more like playing the records without the statics noise.
Like my childrens they have never listen to a record.
I like NOS because it sound more like playing the records without the statics noise.
Possible, but I grew listening to tape, LPs and live - and I prefer OS (with a good output stage).
But I do believe that your references are set early on.
But I do believe that your references are set early on.
In my opinion there isn't much difference between well implemented OS DAC and NOS, like there is not much difference between good tube and good SS devices. The only reason I stick with NOS is because they are much easier to build and tweak 😉
I'm using two DACs, one OS the other NOS, both heavily tweaked, and they sound almost the same, if I didn't know which I'm listening too, I wouldn't probably guess.
I'm using two DACs, one OS the other NOS, both heavily tweaked, and they sound almost the same, if I didn't know which I'm listening too, I wouldn't probably guess.
The evolution of the digital filter
There is an evolution on digital filter. Here is a link from "Ayre" where they give a simple and comprehensive description on the evolution of the digital filter. (The paper is very short and easy to understand.)
The Ayre MP series
You can see the large distance between the first generation of digital filter and NOS concept and the shortest one between last generation of digital filter and NOS concept...
There is an evolution on digital filter. Here is a link from "Ayre" where they give a simple and comprehensive description on the evolution of the digital filter. (The paper is very short and easy to understand.)
The Ayre MP series
You can see the large distance between the first generation of digital filter and NOS concept and the shortest one between last generation of digital filter and NOS concept...
Hello Peter,
The problem is more complex when you want to use other DAC chip like PCM1704, PCM1702, PCM56... Bit alignment need more glue logic; it's the reason why most of NOS DAC is made with TDA154X.
I totally agree with You.
Yes, if you want to use TDA1541, TDA1543, TDA1547...
The problem is more complex when you want to use other DAC chip like PCM1704, PCM1702, PCM56... Bit alignment need more glue logic; it's the reason why most of NOS DAC is made with TDA154X.
no-no, make a poor OS DAC is much more easely
not bad article for beginners, but some pretty funny moments, also as in their website
1547 is from other world, it is Switched capacitor dac(pulse density modulated output) with integrated 2 opams (MOSFET input, bipolar output), need DF and DS modulator before it
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