linuxaudio.org

Folderol wrote:

quoted text
> On Fri, 28 May 2010 19:20:54 +0200

> Ralf Mardorf  wrote:

>

>

>> Veronica Merryfield wrote:

>>

>>> On 05/28/2010 02:31 PM, fons@kokkinizita.net wrote:

>>>

>>>

>>>> Hello all,

>>>>

>>>> This week I had to perform measurements on a audio

>>>> interface, and this resulted in some quite interesting

>>>> results. Before revealing what happened, I'll let you

>>>> have a look at some of the data and come up with your

>>>> own conclusions, see

>>>>

>>>>

>>>>

>>>> (Free beer at the next LAC for the best analysis)

>>>>

>>>> Ciao,

>>>>

>>>>

>>>>

>>> You can't trust a loop back test.

>>>

>>> Any instability or dither on the reference clock of card A (fifo clocking say) is not going to show in a loop back test.

>>>

>>> Vrnc

>>>

>> Is Veronica Merryfield the winner?

>>

>

> I'm highly suspicious of the USB link, but can't quite put my finger

> on why.

>   

Card A is the USB card. For USB there could be several issues, but I

don't have knowledge about buffering etc., but I guess it's card A and

that there's  a "instability" = jitter. I don't know what dither for CLK

is. I guess the winner is Veronica Merryfield.

_______________________________________________

Linux-audio-dev mailing list

Linux-audio-dev@lists.linuxaudio.org

http://lists.linuxaudio.org/listinfo/linux-audio-dev