Khadas tone board external power

[Lucaxxaa]

Hello. I use the same power supply, that have two +5volt exit, for supply raspberry and khadas.

I use this cable, that divide signal from power, then the power of to khadas from power supply and not from raspberry.

https://www.audiophonics.fr/fr/cabl...our-alimentation-et-donnees-20cm-p-14052.html

The problem is that the sound have high distortion.

To resolving, I must disconnect khadas manually from power and reconnect it, then sounds is good.

Why ?
Thanks

 

[gvl]

I don't know why this happens but I have a similar issue when powering KTB from Schiit Wyrd and using SPDIF. When I flip the switch on the Wyrd KTB distorts, I need to unplug it and plug it back in then all is good. There may be some initial supply voltage instability that confuses the KTB and it fails to initialize properly. Try a different PSU maybe.

 

[Gradius]

Did you tried a ferrite on that cable? Sounds like an initial EMI problem / ground problem.

raspberry3 has high noise on USB ports, it was corrected on v4.