Which DACs bypass digital filtering?

[Jud]

5 hours ago, opus101 said:

 

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.

 

That's interesting, since of course there is plenty of IM from natural ultrasonic sources when listening to live unamplified music or just natural sounds.

[Jud]

Something similar to what I was saying above, from @barrows in another thread:

 

Quote

 

What is perceived as a reduction in high frequency energy, often is a reduction in distortion, and hence, more accurate.  I have run into this type of "problem" many, many times in my experience doing customer service and trying to help customers/dealers achieve the best sound.  One might change something in their system which we know is an improvement, from a technical perspective (measured lower distortion/noise), but then they find the system perhaps lacking in "air".  The reality is that the "air" they heard before was really an artifact, and not accurate.

 

If we rely only, and completely on subjective listening tests, without also applying a technical understanding, and measurements where possible, we can often go down "wrong" roads, and get detoured away from accurate sound in playback.

 

 

[elcorso]

3 hours ago, Jud said:

Something similar to what I was saying above, from @barrows in another thread:

3 hours ago, Jud said:

 

What is perceived as a reduction in high frequency energy, often is a reduction in distortion, and hence, more accurate.  I have run into this type of "problem" many, many times in my experience doing customer service and trying to help customers/d

 

 

This subject has always left me intrigued ... How to know if said "air" comes from a very good recording and not "from artifact, and not accurate"

 

Roch

[Jud]

Deleted.

[Jud]

35 minutes ago, elcorso said:

 

This subject has always left me intrigued ... How to know if said "air" comes from a very good recording and not "from artifact, and not accurate"

 

Roch

 

The only way I'm aware of is to use measurements to see what was in the file and what came out of the DAC (or filter software).

[elcorso]

On 6/25/2018 at 8:37 AM, The Computer Audiophile said:

 

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. 

 

Sh*t  happens when you do not use a Mac ?

 

Roch

[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?)

[barrows]

On 6/24/2018 at 11:56 PM, 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.  

2 things to consider:

 

1.  Do you connect to your DAC directly to a computer which is doing the oversampling?  If so, then the extra computer resources needed to oversample will cause more noise to get from the computer to the DAC, and hence, you may prefer the less noise approach of NOS, despite the technical benefits of oversampling.  The solution for this is Ethernet connection via an Ethernet Renderer (like Sonore, etc), as this allows the computer doing the oversampling to be far away from the audio system, where it can do no harm, regardless of how hard it is working (processing power required for oversampling). 

 

2.  If you oversample using integer rates (2x, 4x, 8x, 16x, etc) the "original discrete samples" are not discarded at all, and their ""more precise"" amplitudes are not lost.  Although, with computer based oversampling with much more precise algorithms than what is typically done in DAC hardware based oversampling I do not perceive even non-integer oversampling as a problem.  In any case, with integer oversampling the idea that the original samples are "discarded" is entirely false, they are intact at exactly the same value as before.

[diecaster]

Well, the samples are there with integer rates...but, if a closed form filter is not used then the original samples are lost.

[semente]

Can the T+A DAC 8 DSD be run NOS and digital-filterless?

[Miska]

1 hour ago, semente said:

Can the T+A DAC 8 DSD be run NOS and digital-filterless?

 

Yes, the DSD side is such always. PCM side not... So depends on how you use it.

 

[semente]

14 minutes ago, Miska said:

 

Yes, the DSD side is such always. PCM side not... So depends on how you use it.

 

 

Interesting, thanks.

It's possible alternative to the RME or the Holo for upgrading my UD-501.

[Miska]

40 minutes ago, semente said:

Interesting, thanks.

It's possible alternative to the RME or the Holo for upgrading my UD-501.

 

Of these, RME has DSD Direct mode for playing DSD. And for PCM it has digital filter disable option. And if you input 352.8 - 768k PCM it's digital filters are bypassed anyway. With PCM input it is however always oversampling (at least with S/H aka ZOH).

 

Holo being more similar to the DAC8 DSD as having two separate DACs for PCM and DSD. But with the difference that also PCM side is discrete R2R and both PCM and DSD side can be run NOS without digital filters.

 

All three are good DACs, but somewhat different, so largely depending on how you exactly want to use them. And for DAC8 DSD it is good to consider Amanero firmware vs OS support.

 

[semente]

1 hour ago, Miska said:

 

Of these, RME has DSD Direct mode for playing DSD. And for PCM it has digital filter disable option. And if you input 352.8 - 768k PCM it's digital filters are bypassed anyway. With PCM input it is however always oversampling (at least with S/H aka ZOH).

 

Holo being more similar to the DAC8 DSD as having two separate DACs for PCM and DSD. But with the difference that also PCM side is discrete R2R and both PCM and DSD side can be run NOS without digital filters.

 

All three are good DACs, but somewhat different, so largely depending on how you exactly want to use them. And for DAC8 DSD it is good to consider Amanero firmware vs OS support.

 

 

I will be upconverting to DSD and am currently enjoying the -ext2 filter with convolution, but my 2012 i7 MBP is barely coping...

I'd surely need a new laptop to explore the best that any of those DACs has to offer.

[Miska]

4 minutes ago, semente said:

I will be upconverting to DSD and am currently enjoying the -ext2 filter with convolution, but my 2012 i7 MBP is barely coping...

I'd surely need a new laptop to explore the best that any of those DACs has to offer.

 

DAC8 DSD is good on Windows. And with Amanero beta firmware I've heard reports that it works up to DSD256 on Linux. Flashing the beta firmware to the USB controller is a bit of hassle though (just be prepared if you want to do it). Connected to directly to Mac you'd be limited to DSD128.

 

If you want to connect directly to Mac, ADI-2 goes up to 768k PCM and DSD256 so you get everything it supports. I think Spring 2 should work just fine up to 768k PCM and DSD256 on Mac too, I just have not yet tested that myself.

 

[semente]

1 minute ago, Miska said:

 

DAC8 DSD is good on Windows. And with Amanero beta firmware I've heard reports that it works up to DSD256 on Linux. Flashing the beta firmware to the USB controller is a bit of hassle though (just be prepared if you want to do it). Connected to directly to Mac you'd be limited to DSD128.

 

If you want to connect directly to Mac, ADI-2 goes up to 768k PCM and DSD256 so you get everything it supports. I think Spring 2 should work just fine up to 768k PCM and DSD256 on Mac too, I just have not yet tested that myself.

 

I'm using a Cubox with the NAA image. Would this work well with the T+A?

[volpone]

1 hour ago, Miska said:

DAC8 DSD is good on Windows. And with Amanero beta firmware I've heard reports that it works up to DSD256 on Linux. Flashing the beta firmware to the USB controller is a bit of hassle though (just be prepared if you want to do it).

 

Confirmed. I'm using DAC8 DSD and NAA. DSD256 OK, no issues on Linux with AMANERO USB receiver beta firmware 1099c. 

 

Flashing AMANERO beta firmware to the controller is now quite easy using new "service mode" available from DAC8 DSD FW version 2.7. I presume T+A delivers new DAC's with 2.7+ version (if not DAC FW update procedure is available from T+A).

[barrows]

I can also confirm perfect DSD 256 performance with Amanero USB interfaces running on 1099c via Sonore Rendu renderers (linux based).  This is with Native DSD (no DoP).

[Miska]

3 hours ago, semente said:

I'm using a Cubox with the NAA image. Would this work well with the T+A?

 

IIRC, it should work fine with the beta firmwares to the extent beta firmwares work.

 

[Henley]

Audio Note

EC Designs

[Jud]

14 hours ago, semente said:

I'd surely need a new laptop to explore the best that any of those DACs has to offer.

 

A desktop CPU would run HQPlayer's filters better and probably cost less.  (I think the filters and modulators used by Audirvana+ are probably a bit easier on CPUs, but installing the software you'd need in order to run both UPnP/DLNA and NAA on the CuBox would be rather a PITA IMO.)  And you wouldn't need to have the desktop in the listening room when using an NAA. 

 

However, if you wanted the computer for other uses as well, and needed the portability of a laptop, then of course you can forget all of the above and just look for a replacement laptop.

[Miska]

-2s filters run pretty fine up to DSD512 on my quad-core i7 laptop, it has also Nvidia graphics. Lenovo T470p which I purchased with fastest possible i7 CPU... It wasn't cheap, but certainly relatively cheap compared to any current MacBook Pro...

 

But it is my portable development machine, running Ubuntu 18.04 LTS.

 

Biggest down side with laptops is that even if you can get a really fast one, at higher CPU loads the fans get really loud because they are small and thus run at high RPM to move enough air... On a desktop machine one can have sound proofing and number of slowly rotating 15 cm fans that are practically dead quiet. Like my i7-6950X machine with GTX1080 graphics. It doesn't make any sound that could be heard at listening position. Plus of course there's possibility to have a bit slower machine with passive cooling, that is still pretty much as fast as fastest laptops.

 

[semente]

1 hour ago, Miska said:

-2s filters run pretty fine up to DSD512 on my quad-core i7 laptop, it has also Nvidia graphics. Lenovo T470p which I purchased with fastest possible i7 CPU... It wasn't cheap, but certainly relatively cheap compared to any current MacBook Pro...

 

But it is my portable development machine, running Ubuntu 18.04 LTS.

 

Biggest down side with laptops is that even if you can get a really fast one, at higher CPU loads the fans get really loud because they are small and thus run at high RPM to move enough air... On a desktop machine one can have sound proofing and number of slowly rotating 15 cm fans that are practically dead quiet. Like my i7-6950X machine with GTX1080 graphics. It doesn't make any sound that could be heard at listening position. Plus of course there's possibility to have a bit slower machine with passive cooling, that is still pretty much as fast as fastest laptops.

 

 

Is it possible to use the graphics card of my laptop?

https://everymac.com/systems/apple/macbook_pro/specs/macbook-pro-core-i7-2.6-15-mid-2012-unibody-usb3-specs.html

 

If it is possible, how do I set it up?

[Miska]

3 hours ago, semente said:

Is it possible to use the graphics card of my laptop?

https://everymac.com/systems/apple/macbook_pro/specs/macbook-pro-core-i7-2.6-15-mid-2012-unibody-usb3-specs.html

 

If it is possible, how do I set it up?

 

Yes, with Nvidia GPU's it is possible, to some extent use, given new enough drivers (which tend NOT to be available for macOS). But since the GPU is not especially powerful, likely it would be only useful for limited convolution engine cases.

 

[semente]

3 hours ago, Miska said:

 

Yes, with Nvidia GPU's it is possible, to some extent use, given new enough drivers (which tend NOT to be available for macOS). But since the GPU is not especially powerful, likely it would be only useful for limited convolution engine cases.

 

Thanks.

I have downloaded and installed the MacOS driver. Apparently my laptop can now do -xtr plus convolution without glitches. I'll try a few more tracks.