Digital Signal Transmission

[asdf1000]

14 hours ago, PeterSt said:

Not only because they may present a cleaner (regenerated) signal, but because they will just have a different radiation pattern. Ehm, for better or for worse, because definitely no manufacturer is taking that into account; this is totally out of our control, which is already caused by how devices are inter-linked.

 

Rob Watts talks about RF all the time for years now on Head-Fi forum. He describes it like a "fungus" that gets to all parts of a DAC. Increases IM distortion 

[asdf1000]

5 hours ago, Miska said:

IMO, SINAD alone is as useless figure as any other number taken out of context. I don't think it helps saving $$$.

 

This is true but we all know which site made SINAD a focus but let's not forget his APx555 measures a bunch of other things too, not SINAD alone...

 

His measurements have caught one company getting maximum SINAD at the cost of much higher than normal output impedance.

 

[asdf1000]

7 hours ago, PeterSt said:

Sadly, No. There is no such thing as noise to be measured in the context of audio data, as the HF protocol frequency data *is* noise to the audio domain. There's really nothing to measure there.

Tom didn't mention anything about audio domain there though ?

 

He only said "- Noise reduction - could be measured"

 

And last update I saw a couple years ago was John Swenson is custom building a very high resolution A to D to be able to show these (noise?) measurements? If it was only audio domain then I don't think he would be going to such efforts...

[asdf1000]

3 hours ago, Confused said:

Slightly off topic I know (not that this thread is on topic anymore), but could I ask which manufacturer you are referring too in the above.  It is an interesting comment, because in my experience there is a very real relationship between output impedance and certain aspects of sound quality.  (I am assuming the above refers to an amplifier or maybe a headphone amp) 

 

It's a bit silly we can't post links to the site here but here it is and here is Amir's comment about it.

 

https://www.audio “science” review/forum/index.php?threads/smsl-m400-balanced-usb-mqa-dac-review.13732/

 

 

So he's not just talking about it's SINAD of 121dB, so I'm not sure why people just seem to talk like this is the only measurement he shares.

 

 

 

 

 

[asdf1000]

2 hours ago, TomJ said:

I only whant to find objective answers how the digital transmission can make digital data sound different.

 

1. Ground/leakage currents getting through DAC

 

2. RF - conducted and/or radiated

 

Both of these could be related. Some call these 'RF currents'.

 

Of course the better DAC designers already know this and design to minimise the effects.

 

Better DAC designers doesn't mean crazy expensive products either.