Re: [linrad] Crosstalk between input and output of a SBPC128 soundcard ?

["John Harrison, NI1B" <jmh6@xxxxxxxxxxxxxx]

Hi All,

   Yes, I have had this problem on several audio cards. It seems to be
card specific. Perhaps it is a chip defect, more likely Linux isn't
loading some, unknown to it, card register with the correct value.

   While we are on the subject of audio cards. Older cheap ISA cards seem
to be of MUCH higher quality than more recent cheap PCI audio cards. 

    Some problems I have noticed:

    No anti-aliasing filter - seen a noisy spectra and many spurious
signals
    Card driver consumes great amounts of CPU time leaving little
processing time for Linux.

    You might try a different brand of card and make a few simple
measurements on it.

    warm regards,
    john


On Mon, 16 Jun 2003, Pierre Vanhoucke wrote:

> Hi all,
> 
> When I activate the baseband graph , the spectrum on  the low-end range  of  the waterfall graph is is affected in the following way:
> In the range between 0 and about 500  Hz the noise level of the waterfall graph raises significantly and displays a 1/F pattern. 
> This fenomenon is aggravated when the volume-control of the baseband graph is set to a higher level.
> I suspect cross-talk between the input and the output channel of my Soundblaster PC128 card.
> Has anyone experienced a similar behaviour on his configuration with perhaps an other type of soundcard?
> I there another  way to  disable the output of the baseband graph than setting the ouput-volume to minimum?
> Thanks fo the feedback.
> 
> 73,
> 
> Pierre/ON5GN
>  
> 



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