[ltp] again with proper subjetct: audio line-in not working

[Richard Neill]

:phaidros wrote:
>>There is an extra "redundant" switch to enable the recording. Try the
>>following:
>>
>>amixer sset 'Mic Boost (+20dB)' on      #Enable the Mic boost
>>amixer sset 'Mic' mute                  #Mute the Mic
>>amixer sset 'Mic' cap                   #Set the Recording source to Mic
>>amixer sset 'Capture' cap               #Set the Capture device to
>>                                        #record
>>amixer sset 'ADC' cap                   #Set the ADC to record
> 
> 
> amixer: Unable to find simple control 'ADC',0


..which implies that your thinkpad isn't quite the same as mine!


> mic input is there. no problem. as expected the left channel (mono)
> gets signal from the jack.
> 
> 
>>Then once that works, try gnome-alsamixer to change from Mic to Line-in.
> 
> this doesn't work.
> 

OK - at least we know that the recording and capture part is working ok.
That's usually the hard bit.

> 
>>Extra diagnostic: if you unmute the line-in, can you hear it through the
>>speakers? If not, you may find that the hardware is dodgy, or that you
>>have got line-in re-configured as the rear-output in 5.1 sound!
> 
> that seems to be the issue.
> getting signal from line-in is not possible. its -59db.
> where can I see if it is configured for 5.1 ? (who does 5.1 on thinkpads ??;) )
> 
>

I think you just have to play with the settings. Do you have anything
obvious in the mixer controls? Eg "Line In as Center" or "Duplicate
front output" ?

Try plugging some headphones into the line in and see whether you hear
anything?

Also, it's probably easiest to test line in while feeding the signal to
the speakers, rather than recording and playing back.

Lastly, sometimes the buttons take a second or so to have an effect.


Richard