User Configuration Dunno - Capture from 3 sources?

[inukaze]

Hi there, i am Slackware(64) 14.2 [i had both version 32 & 64 Bits in different partitions]. i had the follow dunno :

Its possible configure alsa to enable record from 3 different sources each with volume control ? because i am trying to configure alsa to capture from single sound card : Mix, Mic & Line

Please, another users read this, i don't want nothing of pulseaudio, i really don't like it.

I ever see i can record from one source and i just can choose one from various options available

Well Suppose the follow, i want

1) Play a background music (mix)

2) Record my voice from the mic connected in the Mic Jack Port of SoundCard

3) Record the notes i press, from my midi keyboard connected in the Line Jack Port of Sound Card.

i want to know if really is possible to configure alsa to make something like (this is mockup make it by myself on gimp)

Because i had days searching information but ever are examples or configuration for use with two or more sound cards.

like this :
http://www.jrigg.co.uk/linuxaudio/ice1712multi.html

or this another one :
https://stackoverflow.com/questions/8043912/is-it-possible-to-capture-both-mic-and-line-in-at-the-same-time-using-alsa

I had publish this originally on this Slackware Forum -> https://www.linuxquestions.org/questions/showthread.php?p=6116801#post6116801

i think this can be done writing correctly the file ~/.asoundrc but i no had idea which things i need, because i try to run

man alsa

Output :
Don't exist any page about alsa

And well without examples or which things i can configure inside that file i need help for that.