2. digital
  3. 154452-3549

Why you want upsampling and upconversion in a server and why it sounds way better!

One of Roon's and Jrivers best advantages is the ability to digitally reprocess your data. 

With an appropriate server you can take for example a 16 bit 44k Tidal stream and reprocess that data stream to DSD or to reprocess to 24bit 192k, 384k, even up to 768k.

In our tests almost accross the board most listeners perfer DSD or high res PCM data streams.

The counter arguement is that if you start with 16 bit 44k sample you can't do any better as that  is the source.

Going through Facebook we got a post that showed the Lumiere brothers first film shot in 1894 with a steam locomotive. 

The second video showed the same Lumiere video reprocessed using AI to create a 4k video stream out of the same video footage. 

The first video is the native source the second shows the reprocessed video the differences aren't subtitle even if you reprocess the native video you are able to extract a signifigantly higher quality image. 

We have been saying this for years even if you don't start out with a true high res source through the magic of computer reprocessing you can create a pseudo high res data packet that still sound far better than ifs original form.

https://arstechnica.com/science/2020/02/someone-used-neural-networks-to-upscale-a-famous-1896-video-to-4k-quality/

Watch the video and see what you think. Sure it is always best to start with a true high resolution image but in the case of not having a true high resolution music fille the ability to use digital reprocessing can create a signal that will sound far better providing that your dac and server are up to the task.

Dave and Troy
Audio Doctor NJ



 
128x128audiotroy

Showing 9 responses by erik_squires

erik_squires
15,824 posts
 
For me, all roads have lead back to native frequencies. I have yet to find any DSP combination in Roon that is more appealing than a native file,


I don't really care for the upsampling to DSD. In PCM mode it seems harmmless, but I do use the EQ features due to room issues and speaker placement.
erik_squires
15,824 posts
 
maybe it is a function of the USB input from n the earlier Brooklyn DAC?

Maybe.  :) It definitely feels like a software/timing glitch to me. Coax/optical have no handshake. The DAC must continuously monitor the incoming signal and sync to it, unlike USB where there is definitely a handshake and after that the DAC pulls each frame.

Best,

E


erik_squires
15,824 posts
 
I remember you saying previously that your Brooklyn gave issues occasionally when switching between differing resolution rates.

Not sure if that is a trait of the Brooklyn though as I cannot say I ever had it happen on my Brooklyn?



I’ve had at least one other person say it happens to them as well, but did not delve further. I’m listening exclusively to PCM via USB. This may not happen over coax or optical. It is not a big enough deal for me to ask it to be fixed, I just hope some day to be able to afford to trade it in for a Manhattan. :)

Also, I have kind of suspicions it has to do with how hot the DAC gets, so I try to leave it elevated and away from the amp.

I know this happens when I hear music, but it sound like beez are buzzing around in the speakers. I have to switch back to whatever mode it is stuck in, and then switch again.

Also, it has done this with a variety of Linux servers and software (Squeezelite, Roon) acting as sources. Would be interesting if this was for instance a Linux driver only sort of issue.
erik_squires
15,824 posts
 
OK, having just done some informal comparisons I am now absolutely ready to render the definitive verdict on the subject. For me. :)

I went from straight PCM streaming to DSD 128. I agree with @rossb - Mostly what I heard was in the range of cymbals. Little that I heard was all that in terms of information, it felt like the top 2 octaves were turned up, and far too much at the cymbal range.

It did not seem natural, but I can see why in a quick listen it may be impressive. I did not hear better sound stage for instance, or deeper fuller bass. What I heard was in the range of selecting different filter settings in a DAC.

In the end, I’m not keeping this setting active. If I want the same effect I'll turn the treble up.
erik_squires
15,824 posts
 
So I just tried upsampling to DSD 128. It takes up about 5-10x more CPU in the Roon server, I think this is as high as I can go with my pokey A10 CPU.

My DAC (Mytek Brooklyn) has issues switching sample rates. Sometimes it glitches, which is annoying when going from my personal library to MQA/Tidal to internet radio. It doesn't happen every time, but it is annoying, so sample rate converting to a common standard removes this issue.

I'll see if it sounds any better to me. :)

Best,

E
erik_squires
15,824 posts
 
I use Roon to upsample my Lumin T2 playback to DSD 512.



Well, that's an interesting idea I should try. I've been upsampling PCM to PCM, not to DSD.  So far it wasn't really worth it. Thanks @tuberist for the suggestion.
erik_squires
15,824 posts
 
In our tests with many high end dacs the upconverted data nearly always sounds far better than the original. 


I have not experienced this in a very long time.
erik_squires
15,824 posts
 
video upconversion adds noise. And neither is acceptable if you’re a purist.


The AI based video upconversion is something brand new and cool. They teach an AI to extrapolate textures, but they are all just guesses. The AI is just adding aesthetically pleasing candy.
erik_squires
15,824 posts
 
I have to agree with @tom6897

The AI is actually adding texture.

Mind you, Sony claims they do the same with some of the MP3 restoration work they are doing, but up and oversampling algorithms do not. At worst, they extrapolate a line. At best they use a curve fitting algorithm. Far from AI based, but interesting to think about for the future.

In my mind, DACs used to perform better with high rez data, and that's changed recently. The quality of performance between Redbook and high resolution has vastly improved.


Best,

E
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