Microphone works on Lenovo Ideacentre 510S-07ICB

I bought my Lenovo desktop PC in March this year:

https://bkhome.org/news/202003/mke2fs-created-wrong-block-size.html

https://bkhome.org/news/202003/documentation-for-lenovo-ideacentre-510s-07icb.html

Some of the guys testing the latest EasyOS, version 2.5, have reported the microphone not working, so I thought had better check it out. I don't have a microphone, so went shopping...

Officeworks here in WA have a headset for only AU$5.00, on the purchase-list for school kids. It comes in two versions, with two 3.5mm plugs, and with a single 3.5mm combo-plug. Modern laptops, and also my Lenovo, have this combo-plug -- nicely located on the front panel.

https://www.officeworks.com.au/shop/officeworks/p/keji-single-plug-pc-headphones-black-kj20m01

The headphone worked immediately, however, running "Record" in 'mhWaveEdit', no audio.

So, started 'AlsaMixer' and bumped up everything labelled "Mic", still no joy. So then ran the default audio mixer, 'aumix', and found that bringing "IGain" above zero, then recording worked.

mhWaveEdit has real nice level gauges for left and right channel, so I was able to set "IGain" to suit my speech. Got to show a snapshot, really nice to have those gauges, can speak and adjust the gain until get a good level, but not clipping:

This is good, but has got me thinking. 'aumix' is an OSS mixer. It relies upon OSS kernel drivers, that are loaded by /etc/init.d/10alsa, whereas AlsaMixer is a pure ALSA mixer.

When I was experimenting with PulseAudio, there was some documentation that do not load those OSS drivers, as they will grab the audio and PulseAudio won't work.

Hmmm, why is there an "IGain" in 'aumix', but I cannot see anything equivalent in 'AlsaMixer'?

Maybe I should experiment with retiring OSS support entirely, not load the OSS drivers, and use 'Retrovol' ALSA mixer instead of 'aumix'. Years ago, I had a problem with Retrovol crashing on ARM boards, which was why I went over to 'aumix'. But, I think 01micko is using 'Retrovol' with his RPi Puppy distro. Will give this some consideration... 

Tags: easy