28 May
2010
28 May
'10
8:07 p.m.
Ralf Mardorf wrote:
Olivier Guilyardi wrote:
And more:
Clock jitter would cause AM (<-- not my knowledge, somebody else wrote
it) instead of analog hum, that would cause an additive signal.
@ Oliver: Didn't you talk about syncing both cards? That's irrelevant.
On 05/28/2010 07:36 PM, Ralf Mardorf wrote:
Did you also say for what card? A or X? If so, is Oliver the winner?
Btw.:
Ralf Mardorf wrote:
Folderol wrote:
I mentioned the clock problem first ;-) However, I thought it the
other way
around: I said that clocks being asynchronous that would generate
artefacts, but
Veronica seems to say that these are hidden when using a single clock.
That's pretty much the same thing to me :p
--
Olivier
On Fri, 28 May 2010 19:20:54 +0200
Ralf Mardorf <ralf.mardorf(a)alice-dsl.net> wrote:
> Veronica Merryfield wrote:
>
>> 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.
Gabriel Beddingfield wrote:
Is the jitter caused because of residual ripple?
Summarized:
Residual ripple for the DC could cause clock jitter and this for card A. On Fri, May 28, 2010 at 12:39 PM, Gabriel M.
Beddingfield
<gabrbedd(a)gmail.com> wrote:
On card A or X?
Why AM and not additive signals? The 100 Hz (being 2x 50Hz, the power freq. in
Italy)
suggests that it is probably related to some manner of
power supply. However, I have no theory why we're
getting 2x 50Hz (and I think I need one :-)).
Doh! When the AC wave is rectified, it results in a signal that is 2x
the freq. because the negative part gets inverted. That's why we see
100 Hz instead of 50 Hz.
-gabriel