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RE: [linrad] Sound card problem?

Hi Matthieu,

> Without any microphone connected to the sound card I have this problem:
> If I increase the sound level (using the red bar) a strong spur 
> appears on the fft display centered on the frequency of the pitch 
> I have set. 

The sound cards have analog "switches" that are used to connect the
different analog signal sources to the ADC input and to the loudspeaker
output. These switches are set by a "mixer program". Each sound system
has it's own "sound mixer program" which has to be configured to fit
the soundcard you use. Under OSS the command to ossmix is llinesw OFF 
and rlinesw OFF. I am not familiar to the other sound systems, but
presumably there is a "mute" button somewhere.

On portable computers it may be more difficult (or impossible) because
the manufacturers do unspecified things to the hardware and supply
drivers for Windows only:(


Leif / SM5BSZ