Can delta sigma dac bypass oversampling filter?

[derekchan]

My avr built in 9018k2m. Anthem mrx740
My streamer built in ak4191eq plus 4499ex
Eversolo a8

I know delta sigma dac need to process oversampling to d/a conversion.
But ess specsheet mention they could bypass oversampling filter ,maybe bypass 256x fs or even 8x oversampling filter .
Go directly to d/a conversion.

How could tell they are nos or oversampling?

 

[staticV3]

How could tell they are nos or oversampling?

By looking at the output with an oscilloscope or soundcard with good treble extension.

NOS will show ugly stair stepping/distortion (left and right column):


Only with oversampling On you will get correct reproduction of the original waveform (middle column).

 

[KSTR]

AKM chips, including the AK4191/4499 offer a "super slow rolloff" filter option which essentially bypasses the digital oversampling filter by simply repeating each sample value N times rather than filtering it. Which gives an true filterless NOS emulation.

 

[DVDdoug]

I was doing some experiments with a soundcard and oscilloscope once and I WAS SHOCKED to see an unfiltered stair-stepped waveform! I had never heard anything "wrong". It was on a cheap computer with cheap computer speakers, but after I thought about it... The harmonics should be well above the audible range, the amplifier in the powered speakers might be limited to the audio range, and the speakers would naturally-mechanically filter-out ultrasonics. They were probably a 3-inch "full range" speakers so no separate tweeter.

I don't remember what the experiment was about but I remember the "surprise" unfiltered output. Sometimes you learn something beyond the intent of the experiment.

...I don't worry about DACs. I never heard anything wrong with the DAC built into my 1st CD player 40 years ago. I've only heard a difference/defect from a "DAC" once, and it was a soundcard that made noise when the hard drive was accessed.

 

[voodooless]

How could tell they are nos or oversampling?

If the don’t make a big deal out of it telling you it’s NOS, it’s not NOS

 

[derekchan]

AKM chips, including the AK4191/4499 offer a "super slow rolloff" filter option which essentially bypasses the digital oversampling filter by simply repeating each sample value N times rather than filtering it. Which gives an true filterless NOS emulation.

Does 9019k2m nos mode or oversampling mode?anthem reject to answer
The specsheet said this delta chip can bypass 8x fs filter...

 

[derekchan]

By looking at the output with an oscilloscope or soundcard with good treble extension.

NOS will show ugly stair stepping/distortion (left and right column):
View attachment 491017

Only with oversampling On you will get correct reproduction of the original waveform (middle column).

May i ask few more
Does s master hx of zx707 da convert without dac chip aka dac less?
How about their volume control?
Is it dsp style digi volume?

2.i own a mcintosh pre amp c8 which feature digital anntentutor but not adjust volume by gain like resistor network volume ic on av receiver.
I am afraid attentution audio will cut sound detail
Like low price dac built in dsp volume control

3.does regular receiver like anthem feature zero negative feedback pre amp section?
Thanks

 

[derekchan]

AKM chips, including the AK4191/4499 offer a "super slow rolloff" filter option which essentially bypasses the digital oversampling filter by simply repeating each sample value N times rather than filtering it. Which gives an true filterless NOS emulation.

My target is a r2r dac but they are high price
Does sokeris or holo audio make a real good r2r chip like pcm1704?
I read 1704 specsheet and found out it feature 8x oversampling in a r2r dac... why ?

4191 specsheet mention it include 256x fs oversampling filter and eversolo didnt mention it is a nos dac

 

[oleg87]

I read 1704 specsheet and found out it feature 8x oversampling in a r2r dac... why ?

For better conversion? Oversampling is a good thing.

 

[voodooless]

May i ask few more
Does s master hx of zx707 da convert without dac chip aka dac less?
How about their volume control?
Is it dsp style digi volume?

2.i own a mcintosh pre amp c8 which feature digital anntentutor but not adjust volume by gain like resistor network volume ic on av receiver.
I am afraid attentution audio will cut sound detail
Like low price dac built in dsp volume control

3.does regular receiver like anthem feature zero negative feedback pre amp section?
Thanks

Why are you chasing all kinds of audiophile nonsense? NOS DACs, non-digital volume controls, zero feedback preamps…

Stop all that, it won’t give you any better sound. Replace fear with knowledge and you will fair much better!

For what it’s worth: for AVR volume controls, most are implemented by a digitally controlled analog volume control chip. I would be surprised if the Anthem is any different. As for the C8, it’s a tube preamp with options digital bits, so no way the volume control is in the digital domain.

 

[JeremyFife]

If the don’t make a big deal out of it telling you it’s NOS, it’s not NOS

It's the same with Vegans

 

[solderdude]

My target is a r2r dac but they are high price
Does sokeris or holo audio make a real good r2r chip like pcm1704?
I read 1704 specsheet and found out it feature 8x oversampling in a r2r dac... why ?

4191 specsheet mention it include 256x fs oversampling filter and eversolo didnt mention it is a nos dac

Filterless NOS is broken by design and why the 1704 does oversampling so it isn't broken.
The very first CDP's actually were the only DACs that did not oversample and had VERY steep analog filters after it.
Philips was not able to make 16 bit chips and found a way around that problem using 4x oversampling (with digital filter) and 14 bits converters to come to 16 bit resolution.
It also meant that the post filtering did not have to be steep (which was difficult to make in analog circuits).
Then the race with more bits and more oversampling was born.

The DS merely emulate a 'sample and hold' (which filterless NOS R2R does).

It's fine to use the inferior R2R converters if you use them with oversampling.
They are good enough not to be audibly different from DS.

You need to understand that R2R (in its various forms) is a simple conversion method that is non linear.
R2R does not mean NOS and does not mean 'reconstruction filterless'.

It seems what you are looking for is not better sound quality but rather poorer quality and more expensive conversion methods for the sake of an illusion that 'R2R' is better somehow.

 

[derekchan]

For better conversion? Oversampling is a good thing.

Sory it is 9010k2m ess
It is weird for delta sigma dac can bypass oversampling filter cause wiki said delta sigma dac handle da conversion by oversampling
If it is design as delta it must be 8x fs oversampling at least

 

[solderdude]

Sory it is 9010k2m ess
It is weird for delta sigma dac can bypass oversampling filter cause wiki said delta sigma dac handle da conversion by oversampling

It is an emulation of filterless NOS DAC and mimics the sample and hold behavior of R2R.
It f's up the intended signal by creating TONS of RF crap that really should not be there.
They do that because the market asks for it so manufacturers offer various filters (knowing they are crap) so they can sell their chips.
When they wouldn't manufacturers of gear would buy chips from other manufacturers that do offer that option.

If it is design as delta it must be 8x fs oversampling at least

It does... many, many more times than 8 times.

 

[derekchan]

Why are you chasing all kinds of audiophile nonsense? NOS DACs, non-digital volume controls, zero feedback preamps…

Stop all that, it won’t give you any better sound. Replace fear with knowledge and you will fair much better!

For what it’s worth: for AVR volume controls, most are implemented by a digitally controlled analog volume control chip. I would be surprised if the Anthem is any different. As for the C8, it’s a tube preamp with options digital bits, so no way the volume control is in the digital domain.

Tda1541 is a greatest nos single chip r2r which bring you natural analog vinyl sound instead of digital analog from delta sigma.

Avr volume control is resistor network volume ic to adjust volume by gain not attentution like variable resistor,digital volume of dsp . They will cut bit if you turn down volume and sound detail lost .

For c8 it is digital attentution wriiten in mcintosh .pdf . I am wondering if it will cut bit like dsp volume control

A good volume control should a adjust by gain like accuphase pre amp

 

[oleg87]

Sory it is 9010k2m ess
It is weird for delta sigma dac can bypass oversampling filter cause wiki said delta sigma dac handle da conversion by oversampling
If it is design as delta it must be 8x fs oversampling at least

I don't entirely understand the ESS converters' inner workings, but as per the datasheet, there's another interpolator after the bypassed one.

 

[staticV3]

I am afraid attentution audio will cut sound detail

See here: https://www.audiosciencereview.com/...ge-edge-a-setup-noob-alert.63726/post-2336108

 

[voodooless]

Tda1541 is a greatest nos single chip r2r which bring you natural analog vinyl sound instead of digital analog from delta sigma.

There is absolutely nothing analog about NOS… it’s pure marketing fantasy. And even the best implementations back then used a 4x oversampling filter.

For c8 it is digital attentution wriiten in mcintosh .pdf . I am wondering if it will cut bit like dsp volume control

What exactly does it say?

 

[KSTR]

I don't entirely understand the ESS converters' inner workings, but as per the datasheet, there's another interpolator after the bypassed one.

DS DACs always use oversampling in the final stage (the DS modulator) because that's how DS works, using some 4..8 bit final DAC and upsampling to a very high rate to get 24bits of resolution. Same trick as used by Philips back in the day, just taken to the extreme.

But for the input of that final upsampler you usually have options, choosing which kind of anti-imaging filter you want to have, including none, and that one gives textbook filterless NOS. Better than the original hardware NOS actually, because of much higher precision of DS DACs

 

[voodooless]

textbook filterless NOS

Technically there is no such thing in DS DAC Any type of mechanism that creates new samples is effectively a filter, even if you simply repeat samples.