[LAU] [SOLVED] Crackles in audio, drifting intermittent noise etc.

Len Ovens len at ovenwerks.net
Tue Nov 1 16:52:42 UTC 2016


On Tue, 1 Nov 2016, Len Ovens wrote:

> So what is different between running two cores or four? Cpu load is higher 
> with two. That would be a Performance/Ondemand governor difference. However, 
> the size of the cycle does not make sense with that. nor the idea that the 
> distortion fades in and out. Speed changes give xrun right at downshift (for 
> me anyway).

Oh, one other difference. The power suppy can be running harder too to 
supply more power for extra cores. look at the temperature when running 
two cores or four. The power supply is a switcher and the delta series 
audio interfaces are known for not taking great care of power regulation. 
See:
http://www.jrigg.co.uk/elec/interface.html
So it is possible power supply ripple at switching frequency is causing 
problems. It seems to me the switching frequency in at least some power 
supplies changes with power output. Of course how well the caps in the PS 
filter ripple is affected by power use as well.


--
Len Ovens
www.ovenwerks.net



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