Multiple Sound Cards, Using Mic Input/Line Ins Simataneously

[Otakugima]

Got some questions.

First off. Can one stack multiple audio injector cards together. As to use both inputs and outputs of both cards? Any driver conflicts.

Secondly, I see in the ALSA mixer that one is given the option of either using the microphone, or line input? Can both be used simultaneously for
effectively 3 mono inputs?

Lastly, I am trying to at least run a guitar and a microphone through this soundcard via pure data. Only way I can figure that out is to
convert the instrument level to line level and run it through? I saw a post where you gave a link to a DI Box but I am looking for the most compact, electronically
efficient way to go about this. Any advice?

[flatmax]

You have to choose between either the line or microphone input. Can't record from both !
As there is only one I2S bus on the GPIO header, only one sound card can be used at a time.
You definately need a preamp to mix down the guitar and mic ... not sure of a more efficient method for doing this !

Matt