Which DACs bypass digital filtering?

[Summit]

Totaldac has some NOS DACs and sound great.

Audio note has many NOS DACs as well.

MHDT has some like Atlantis, Orchid and Stockholm.

[semente]

1 hour ago, Summit said:

Totaldac has some NOS DACs and sound great.

Audio note has many NOS DACs as well.

MHDT has some like Atlantis, Orchid and Stockholm.

 

Thanks.

Asfar as I know, AN DACs are Redbook, and Redbook should be oversampled.

[semente]

- Aqua DACs

- Armature Asterion (same as Holo Spring)

- Audio-GD (some models)

- Border Patrol

- Denafrips DACs

- Esoteric (some models?)

- Lampizator DACs- Spring AudioDACs (some models?)

- Holo 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?)

[Summit]

28 minutes ago, semente said:

 

Thanks.

Asfar as I know, AN DACs are Redbook, and Redbook should be oversampled.

 

Audio note NOS DAC’s can play up to 96 KHz.

[the_bat]

On 14/04/2018 at 12:48 PM, semente said:

....and Redbook should be oversampled.

You keep stating this as a fact. It isn’t. 

[Jud]

9 hours ago, the_bat said:

You keep stating this as a fact. It isn’t. 

 

I suppose it depends on how much distortion you like.  There's a reason oversampling became standard engineering practice in digital audio even before such things as DACs existed.

 

You may like the sound of NOS Redbook, and no one can dispute what you like.  Or you may legitimately question how audible a given amount of distortion may be.  But that lower distortion can be obtained with oversampling is a fact.

[opus101]

54 minutes ago, Jud said:

I suppose it depends on how much distortion you like.

 

Its not that, at least from my perspective as a designer of NOS DACs. Rather its more to do with the dynamic performance of DAC chips. Put it another way, it depends on what proportion of the time you want your DAC's output to be at the wrong value. NOS minimizes this fraction.

[audiventory]

I wrote educational article about NOS DACs.

There is DAC list 2018.

Some of these DACs have no any filtering, as digital as analog.

In the article issues, that caused by non-filtering, are considered.

Read the article https://samplerateconverter.com/educational/nos-dac

 

[Miska]

4 hours ago, opus101 said:

Its not that, at least from my perspective as a designer of NOS DACs. Rather its more to do with the dynamic performance of DAC chips. Put it another way, it depends on what proportion of the time you want your DAC's output to be at the wrong value. NOS minimizes this fraction.

 

NOS DAC runing at RedBook rates never has correct value on the output!  Which is quite apparent from the output spectra.

 

 

Plain sample values are not correct, they need to be reconstructed first to continuous non-discrete time analog waveform.

 

[opus101]

That spectrum looks to me to be an incontinent NOS. By using the TLA 'NOS' I was only referring to the lack of oversampling, not to the lack of filter.

[Miska]

2 hours ago, opus101 said:

That spectrum looks to me to be an incontinent NOS. By using the TLA 'NOS' I was only referring to the lack of oversampling, not to the lack of filter.

 

With NOS DAC running at 44.1k there's no way to have sufficient analog filter that doesn't also completely screw up the audio band. This one has filter, but not much.

 

For proper reconstruction of RedBook (assuming preferred bandwidth of 20 kHz) you'd need analog filter that is -96 dB down by 24.1 kHz. Plus you would need an analog Eq to compensate for the top octave roll-off. That would be quite crazy analog filter having lot of issues. Still same thing even if you would be fine with several orders of magnitude less attenuation, like -48 dB.

 

There's just no advantage in trying to avoid digital filters, you can do all you can do with analog filters and more, without the extra problems.

 

I personally prefer much more this kind of output (in this case same source data, but converted to DSD512 to a "NOS DSD DAC"):

 

[opus101]

11 minutes ago, Miska said:

There's just no advantage in trying to avoid digital filters, you can do all you can do with analog filters and more, without the extra problems.

 

My own aim in designing NOS isn't trying to avoid digital filters. Perhaps other designs have that aim, I wouldn't know. Do you think they have that as an aim?

[Miska]

2 hours ago, opus101 said:

My own aim in designing NOS isn't trying to avoid digital filters.

 

Oversampling == digital filters. Or maybe you want to open up a bit more what is your aim specifically.

 

But anyway I was talking of NOS in context of running NOS DAC @44.1/48k rates on purpose. Output of the same PCM NOS DAC got quite a bit better by upsampling (oversampling) in software to 384k:

 

 

2 hours ago, opus101 said:

Perhaps other designs have that aim, I wouldn't know. Do you think they have that as an aim?

 

Yes, at least Metrum, they got angry at me when I was trying to even discuss about the topic with them (over email)...

 

[opus101]

7 hours ago, Miska said:

Oversampling == digital filters. Or maybe you want to open up a bit more what is your aim specifically.

 

No secret about that - its to get the best SQ at the lowest BOM cost. Adding a digital filter adds to the BOM. Admittedly its not a huge cost up in absolute terms to introduce a $2 ARM SoC but in the context of lowest cost, that is significant.

[Miska]

5 hours ago, opus101 said:

No secret about that - its to get the best SQ at the lowest BOM cost. Adding a digital filter adds to the BOM. Admittedly its not a huge cost up in absolute terms to introduce a $2 ARM SoC but in the context of lowest cost, that is significant.

 

OK, I see. If you do that in playback software, it doesn't add any cost!  If you are already using computer for playback, you can as well utilize it's CPU power, instead of keeping it running do-nothing-idle-loop.

 

Doing the conversion with SDM (DSD) you get both the lowest DAC BOM, highest accuracy and performance.

[opus101]

2 minutes ago, Miska said:

If you do that in playback software, it doesn't add any cost!  If you are already using computer for playback, you can as well utilize it's CPU power, instead of keeping it running do-nothing-idle-loop.

 

Yes, I see. However there's no computer being used for playback, its a portable application.

[Miska]

2 hours ago, opus101 said:

Yes, I see. However there's no computer being used for playback, its a portable application.

 

OK, at this forum I sort of assume people are using computer for playback...

 

My portable application is Lenovo T470p laptop with quad-core i7 CPU and Nvidia GPU, and a DSD512 capable portable DAC.

 

[opus101]

I consider that more in the realm of transportable than portable

[semente]

1 hour ago, opus101 said:

I consider that more in the realm of transportable than portable

 

Sorry, wrong topic. My mistake.

[semente]

1 hour ago, opus101 said:

I consider that more in the realm of transportable than portable

 

This thread is about non-portable, NOS, filterless DACs that can take 24-bit and at least 175.4/192kHz.

[PeteS]

So, if you have eg. Metrum Onyx dac which can take max 385KHz. Would it be optimal upsample

all to it's max resolution? I have never have NOS dac. Interested about topic thou.

[Miska]

19 minutes ago, PeteS said:

So, if you have eg. Metrum Onyx dac which can take max 385KHz. Would it be optimal upsample

all to it's max resolution? I have never have NOS dac. Interested about topic thou.

 

Yes, 352.8/384 and it'll do much much better job on the output quality. Gives you quite a lot of freedom to choose filters you like.

 

[butifull01]

Trinity DAC can bypass perfectly with LIANOTEC.

[semente]

5 hours ago, butifull01 said:

Trinity DAC can bypass perfectly with LIANOTEC.

 

I don't feel like reading the manual.

 

Can the Trinity DAC run in a NOS & filterless mode?

[butifull01]

1 hour ago, semente said:

 

I don't feel like reading the manual.

 

Can the Trinity DAC run in a NOS & filterless mode?

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.