Dell mini 10v - how to turn off built in mic?

[Howard]

I've been using Audacity to digitise some old cassettes of family history interest.  It works fine except that I've discovered that the internal mic is working as well as the external feed from the tape box.  The level is quite low, and I'm generally not around during dubbing, but there is a bit of extra sound and I cannot find any way to switch off the internal mic. I had assumed that plugging in the external feed would do it automatically, but not so.

I'm using LXDE and the alsa mixer.  I don't know much about how the sound system works; so if you have any ideas please explain in some detail.

[Ferdes Fides]

Can't they be set to zero in  alsamixer ?

terminal to alsamixer, arrow key over and arrow key them all to zero.

Otherwise in the computer's BIOS.


Patrick013