Which DACs bypass digital filtering?

[semente]

11 minutes ago, butifull01 said:

Yes

 

Trinity DAC has no analogue/digital filter as well as fuse and regulator.

 

8 PCM 1704 (per channel) arrays make almost noise reduce. Just DAC chips array~!

 

This technology name is LIANOTEC.

 

Right, I'll update the list.

 

[semente]

- Aqua DACs

- Armature Asterion (same as Holo Spring)

- Audio-GD (some models)

- Border Patrol

- Denafrips DACs

- Esoteric (some models?)

- Lampizator DACs

- Holo Audio DACs (some models)

- iFi micro (some models)

- Lampizator DACs

- Metrum Acoustics DACs

- MHDT (some models)

- Phasure NOS1 DAC

- RME ADI-2 DAC

- Teac UD-50x family

- TotalDAC (some models?)

- Trinity DAC

[Jud]

9 hours ago, butifull01 said:

Yes

 

Trinity DAC has no analogue/digital filter as well as fuse and regulator.

 

8 PCM 1704 (per channel) arrays make almost noise reduce. Just DAC chips array~!

 

This technology name is LIANOTEC.

 

LIANOTEC stands for Linear Analog *Oversampling* Technology. 

[mansr]

27 minutes ago, Jud said:

LIANOTEC stands for Linear Analog *Oversampling* Technology. 

That makes no sense.

[Ralf11]

25 minutes ago, mansr said:

That makes no sense.

 

You are supposed to regard it from a pre-postmodern deconstructivist supplementation viewpoint

[butifull01]

1 hour ago, Jud said:

 

LIANOTEC stands for Linear Analog *Oversampling* Technology. 

 

You're right.

 

LIANOTEC is made on the basis of over sampling.

 

According to Trinity homepage's graphs, LIANOTEC makes sound output much purer than bit-perfect.

 

Trinity DAC is not made by high price parts. Almost parts are not customized. Very cheap~!

 

Nonetheless, Trinity DAC price is $ 60,000.

 

The reason is just LIANOTEC.

[Jud]

3 hours ago, mansr said:

That makes no sense.

 

Apparently what Trinity says is that "8x oversampling" is achieved by having 8 PCM1704 chips per channel and having the appropriate phase delays in 7 of them to get 8 output samples per input sample.

[mansr]

44 minutes ago, Jud said:

Apparently what Trinity says is that "8x oversampling" is achieved by having 8 PCM1704 chips per channel and having the appropriate phase delays in 7 of them to get 8 output samples per input sample.

That sounds like an incredibly complex way of achieving, at best, nothing at all.

[jabbr]

59 minutes ago, Jud said:

 

Apparently what Trinity says is that "8x oversampling" is achieved by having 8 PCM1704 chips per channel and having the appropriate phase delays in 7 of them to get 8 output samples per input sample.

??

[Jud]

45 minutes ago, mansr said:

an incredibly complex way of achieving, at best, nothing at all.

 

I am so stealing that.

[jabbr]

It is, of course, a digital filter, 8 bit FIR I guess (depending on how its connected), but upsampling? no.

[buonassi]

probably not a helpful post, but I thought I'd share nonetheless so take it FWIW:

 

Regarding all 44/16 source material, I've found that some magic is lost when I upsample (iZotope via Audirvana) on my Metrum Amethyst (NOS DAC).  No matter what the settings, it just doesn't sound as good to me.  Usually, I prefer the interpolation done by upsampling to that of the OS DACs I have, and can settle in on a configuration that maximizes the sound to my preference.  This is the first time that I couldn't improve upon the sound (to my ears) by upsampling.  So what gives?

 

I think there's something unique to DACs that are designed to not oversample.  I've seen it described by a prominent DAC reviewer on the SBAF site (@hands) as "spooky good stuff".  I have to agree that at least this NOS DAC can present an eery realism to the sound - very organic/relaxed/natural, yet retains good imaging queues and holographic staging.  So yeah, somewhat "spooky" in the regard that it sounds unexpectedly real sometimes.  Especially in the reverb/impulse response characteristics of the room the music was recorded in.

 

I think there's something inherent in the interpolation process that kind of "robs" the music of musicality.  I posit that it is because the original discrete samples with their "more precise" amplitudes are ultimately discarded in favor of an interpolated waveform that is superior (in terms of distortion).  So through an OS DAC, you're hearing a wave form that's been transcribed two times (once via ADC decimation and another through DAC reconstruction).  My theory is that by omitting the latter, you get one step closer to the original wave form.  Yes, at the expense of IMD nasties, etc. 

 

This is my opinion only and I can't back it with any science.  Just the ramblings of one dude in the midst of new toy syndrome.  

[semente]

You're right, it's not really helpful. ?

[semente]

- Aqua DACs

- Armature Asterion (same as Holo Spring)

- Audio-GD (some models)

- Border Patrol

- Denafrips DACs

- Esoteric (some models?)

- Lampizator DACs

- Holo Audio DACs (some models)

- iFi micro (some models)

- Lampizator DACs

- Metrum Acoustics DACs

- MHDT (some models)

- Phasure NOS1 DAC

- RME ADI-2 DAC

- Teac UD-50x family

- TotalDAC (some models?)

[opus101]

55 minutes ago, buonassi said:

So through an OS DAC, you're hearing a wave form that's been transcribed two times (once via ADC decimation and another through DAC reconstruction).  My theory is that by omitting the latter, you get one step closer to the original wave form.  Yes, at the expense of IMD nasties, etc. 

 

If you use a fairly steep analog reconstruction filter - to attenuate those IMD nasties - NOS gets even better IME.

[Jud]

4 hours ago, buonassi said:

probably not a helpful post, but I thought I'd share nonetheless so take it FWIW:

 

Regarding all 44/16 source material, I've found that some magic is lost when I upsample (iZotope via Audirvana) on my Metrum Amethyst (NOS DAC).  No matter what the settings, it just doesn't sound as good to me.  Usually, I prefer the interpolation done by upsampling to that of the OS DACs I have, and can settle in on a configuration that maximizes the sound to my preference.  This is the first time that I couldn't improve upon the sound (to my ears) by upsampling.  So what gives?

 

I think there's something unique to DACs that are designed to not oversample.  I've seen it described by a prominent DAC reviewer on the SBAF site (@hands) as "spooky good stuff".  I have to agree that at least this NOS DAC can present an eery realism to the sound - very organic/relaxed/natural, yet retains good imaging queues and holographic staging.  So yeah, somewhat "spooky" in the regard that it sounds unexpectedly real sometimes.  Especially in the reverb/impulse response characteristics of the room the music was recorded in.

 

I think there's something inherent in the interpolation process that kind of "robs" the music of musicality.  I posit that it is because the original discrete samples with their "more precise" amplitudes are ultimately discarded in favor of an interpolated waveform that is superior (in terms of distortion).  So through an OS DAC, you're hearing a wave form that's been transcribed two times (once via ADC decimation and another through DAC reconstruction).  My theory is that by omitting the latter, you get one step closer to the original wave form.  Yes, at the expense of IMD nasties, etc. 

 

This is my opinion only and I can't back it with any science.  Just the ramblings of one dude in the midst of new toy syndrome.  

 

It's quite possible at least some of us hear levels of IMD as more "warm" or "natural."

[asdf1000]

19 minutes ago, Jud said:

 

It's quite possible at least some of us hear levels of IMD as more "warm" or "natural."

 

Higher levels of IMD = warmer?

[mansr]

9 hours ago, jabbr said:

It is, of course, a digital filter, 8 bit FIR I guess (depending on how its connected), but upsampling? no.

Yes, the design is equivalent to an 8x zero-order hold followed by an 8-tap FIR filter. I'd have to see the actual circuit to say the coefficients are, but I wouldn't be surprised if it is simply summing the DAC outputs. That would be equivalent to a moving average filter, or if you prefer, convolution with a rectangle function. Whatever the weighting, the same result could be achieved better and cheaper by doing the filtering digitally ahead of the DAC. Oh wait, that's what every standard DAC chip does. Can't have that.

[semente]

1 hour ago, mansr said:

Whatever the weighting, the same result could be achieved better and cheaper by doing the filtering digitally ahead of the DAC. Oh wait, that's what every standard DAC chip does. Can't have that. 

 

?

 

 

?

[Jud]

2 hours ago, Em2016 said:

 

Higher levels of IMD = warmer?

 

Possibly, yeah. I think I may hear it that way (I used to like very low steepness settings in iZotope, for example).

[asdf1000]

5 minutes ago, Jud said:

 

Possibly, yeah. I think I may hear it that way (I used to like very low steepness settings in iZotope, for example).

 

Rob Watts (Chord DAC designer) thinks the complete opposite. Higher levels of IMD results in a brighter sound. Warmer = lower distortion.

 

"The actual distortion mechanism is noise floor modulation - random RF noise gets into the analogue electronics, and at RF frequency things are very non-linear. Then you get intermodulation distortion with the audio signal and the random RF noise, giving you random intermodulation products that is in the audio bandwidth. So noise pumps up and down with the audio signal, making it sound harder and brighter. Unfortunately, the brain is very sensitive to this effect."

 

"With analogue electronics, very tiny amounts of RF noise will cause intermodulation distortion with the audio signal, and the intermodulation products is noise floor modulation. The effect is that the noise floor changes with signal level, and the effect is very audible - you perceive it as a brightness to the sound quality. Less noise floor modulation, smoother sound quality. The curious thing about this is that the brain is very sensitive to it, so you can easily hear it. Problem is that many listeners hear the brightness as more detail resolution, and so think it sounds better - but that's another story."

[Jud]

32 minutes ago, Em2016 said:

 

Rob Watts (Chord DAC designer) thinks the complete opposite. Higher levels of IMD results in a brighter sound. Warmer = lower distortion.

 

"The actual distortion mechanism is noise floor modulation - random RF noise gets into the analogue electronics, and at RF frequency things are very non-linear. Then you get intermodulation distortion with the audio signal and the random RF noise, giving you random intermodulation products that is in the audio bandwidth. So noise pumps up and down with the audio signal, making it sound harder and brighter. Unfortunately, the brain is very sensitive to this effect."

 

"With analogue electronics, very tiny amounts of RF noise will cause intermodulation distortion with the audio signal, and the intermodulation products is noise floor modulation. The effect is that the noise floor changes with signal level, and the effect is very audible - you perceive it as a brightness to the sound quality. Less noise floor modulation, smoother sound quality. The curious thing about this is that the brain is very sensitive to it, so you can easily hear it. Problem is that many listeners hear the brightness as more detail resolution, and so think it sounds better - but that's another story."

 

Some folks may perceive brightness as energy and warmth, others as excessive harshness.

 

For example, Vandersteen speakers have a slight midrange hump in frequency response. Most subjective reviews describe it as being on the musical or warm side.  However our friend @semente cannot abide its excessive brightness.

 

People hear differently to begin with. Then they have experiences of "good" reproduced sound that can vary greatly. So unsurprisingly there are as many opinions of what sounds good, or warm, or lively, or harsh as there are different brands of audio equipment.

[asdf1000]

1 minute ago, Jud said:

People hear differently to begin with. Then they have experiences of "good" reproduced sound that can vary greatly. So unsurprisingly there are as many opinions of what sounds good, or warm, or lively, or harsh as there are different brands of audio equipment.

 

Noted. Not saying you're hearing and observations are wrong ?

 

Just sharing another data point, from a DAC designer.

[opus101]

46 minutes ago, Em2016 said:

"With analogue electronics, very tiny amounts of RF noise will cause intermodulation distortion with the audio signal, and the intermodulation products is noise floor modulation. The effect is that the noise floor changes with signal level, and the effect is very audible - you perceive it as a brightness to the sound quality. Less noise floor modulation, smoother sound quality.

 

While I'm in agreement with Rob Watts on the importance of minimizing noise modulation I suspect the subjective effects are rather context-dependent. In my experience the presence of noise modulation hasn't been limited to just perceived brightness, it extends to other factors such as loss of ambience information, greying out of tonal colours, flattening of the soundstage and loss of overall dynamics.

[The Computer Audiophile]

14 hours ago, mansr said:

That sounds like an incredibly complex way of achieving, at best, nothing at all.

 

I once worked with a guy who would open text documents by browsing to notepad.exe then using the File > Open menu. 

 

That was an incredibly complex way of achieving at best, what could have been done by clicking the txt file. At least something was accomplished and he got to read the file.