Hector Martin

Is it odd that I can instantly spot that horrible 1kHz buzz caused by cheap USB soundcards even in professional videos? USB sucks for audio.

@marcan42 Poorly isolated digital signals. (Almost) nothing to do with USB.

@doragasu USB puts audio-frequency currents on the ground pin. There's very little getting around it with unbalanced audio and loops.

@marcan42 You can go self powered and isolate the grounds. Even going bus powered, careful power filtering+isolation can remove the noise.

@doragasu If you have galvanic isolation of the grounds, sure, that works, but that's expensive and rarely done.

@marcan42 but definitely it can be filtered.And filtering 1kHz is way easier than filtering 50Hz. On the other side 1kHz can be heard easier

@doragasu I had a similar issue w/ an Acer, because it had 3-prong AC but 2-pin DC (- and earth are one pin). Horrible ground loop noise.

@doragasu Basically the rule to avoid this is to never send power over signal or earth reference, which is what USB breaks.