Archimago wrote: > Jkeny. Please respond to the question above... Has it been demonstrated > that the 8kHz and 16kHz tone are indeed not just sidebands of the 12kHz > primary 24-bit J-test signal shown by Amir??? > > Unless shown to be the case, no need to speculate about the 8kHz PHY > noise origin and speculations of this being an "improvement" in jitter > performance. As I said in my post "Of course I could be wrong in my interpretation of these 8KHz spurs - more testing is required, I reckon"
You have measured 8Khz & harmonics spurs in USB audio, ArnyK has measured 8KHz & harmonics spurs in USB audio DACs, BE718 has measured 8KHz spurs in his USB audio. What are you asking me? - are Amir's 8KHZ & harmonics shown in his measurements due to the same mechanism as these others? Unless he does a measurement to tease this out, we won't know for sure but I can tell where I's place money! Anyway, it appears that there is a ground loop condition set up by the ground lift resistors in the Regen that is being picked up in any test setup that isn't fastidious about avoiding ground loops & it appears that this is why we are seeing these spurs in some measurements & not others. It appears that the 8KHz is coming from the USB hub chip's handling of the 125uS microframes but with better PS treatment this will probably disappear? ------------------------------------------------------------------------ jkeny's Profile: http://forums.slimdevices.com/member.php?userid=35192 View this thread: http://forums.slimdevices.com/showthread.php?t=104340 _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/mailman/listinfo/audiophiles
