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Can you get "audiophile" sound using a native RP4 USB port into a DAC?
#35
(05-01-2021, 09:38 PM)mxpwladimir Wrote:
(05-01-2021, 06:13 PM)lolli8 Wrote:
(05-01-2021, 02:50 AM)Jandu Wrote: Sound quality is determined by many factors. Some better understood, some not as much. If you believe a different USB cable would change the sound, you would understand that it's not just the 0s and 1s that count.

Hi Jandu, short question: do you have any basic knowledge about physics and maths, plus some basic understanding of computers?

If it would be the case, you would immediately stop telling this nonsense, as soon as you had a look at how the data is transferred over an USB cable. In case you have the required skills (which I doubt), please check the wiki page about pulse density modulation which is the method used to transfer data over an USB port from a network streamer to the DAC.

It takes more than some random noise to have an influence on anything in the data chain here. And yes, all that count are the 0s and 1s, but to explain this a bit in detail you would have to understand maths like fourier transformation, which I also doubt you know what this is.

So please keep your religious aspects (I believe there is more than 0 and 1), but keep these ideas to yourself, so others don't waste money by buying snake oil like you did. At least I agree on one of your points: "some better understood, some not as much", with an emphasis on "not" on your end.

Sorry.

Woah what an arrogant answer, better hold your horses before you ridicule yourself more.

Knowledge only looks arrogant if you don't have the required skills and you have to believe what others say. You will fail to understand where reality ends, and where the "snake oil" stuff starts.
If you don't believe me but think you have enough knowledge, do the following. Based on your response you should be clever enough.
1) Look up https://en.wikipedia.org/wiki/Datei:Puls...lation.svg . You can find a sample code written in Python. Take that one or translate it into the programming language you know.
2) Add second sinus wave with a lower frequency and a lower amplitude.
3) Run the program to generate the density-pulse data format (the 0 1 0 1... bit format). This is what your USB port is sending as data.
4) Go back to the program and change the amplitude of the wave you have added in step 2) and repeat step 3)
5) compare the output of the two formats and spot the differences.

If you want to change the sound in any way (doesn't matter if you call it quality, enhancement, "more clean"), then your cable or whatever equipment you use/exchange will have to modify these bits in exact the same way to achieve what I have done in step 3-5 by changing the underlying sound data. This is required because the DAC on the other end of the cable only translates digital data but not best wishes or high hopes. Same data leads to same results.


Now consider the following details: If you apply the bit corrections in the wrong place, you end up with chaotic sound, so you need to switch the exact correct bits in the right places.
These bits are send in the same frequency the signal was encoded, which is 2.8 MHz. You need at least a frequency with the same or even higher to be fast enough to apply the changes. Electricity has 50Hz and even the fastest switching "dirty noise generating" power supply is maxed out 1.6 MHz., but the switching frequency typically is in the range of 10-50 kHz.
There is zero chance to modify the data stream in a way like done, because there is no equipment in the data chain to do this, and any element which would be fast enough doesn't know at which point the data stream must be modified. This especially applies to USB cables without any computing power.

SO: any comment about the enhancements ("better bass") are simply classified in the same way like placebo. 
But please, prove me wrong. It's easy, only some lines of code.


Messages In This Thread
RE: Can you get "audiophile" sound using a native RP4 USB port into a DAC? - by lolli8 - 05-03-2021, 04:06 PM

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