I am a Linux newbie. I know my way around the command-line enough to where it doesn't get in the way of my day job (I develop web applications in Python). This involves some piping, grep, awk, and programmer-oriented stuff like that.
I am experimenting with desktop Linux on my home computer (using Ubuntu). I am trying to set up Jack, as I've heard it's the Linux equivalent to ASIO on Windows. I play guitar for fun and thought it would be cool to play with Ardour or find a FOSS equivalent to Guitar Rig.
However I do not understand... well, anything. I don't understand what Jack does. From what I can gather, the general flow is
[sound hardware] →
(Phonon comes in because I use KDE. I think.)
I don't actually know what the arrows represent. The JACK website contains essentially zero beginning user oriented documentation, except for one page describing how to use JACK with PulseAudio.
As a beginner who, regardless of JACK, doesn't understand how sound works in Linux, where can I go to learn? I'd like to gain an understanding of the sound stack. But for JACK all I was able to find is its barren Wiki (including two juicy links named Configuring and running a JACK server and Setting up a simple audio chain, which both turn out to be "Coming Soon" pages which haven't been edited in five years) and a Linux Journal article from 2005.
Many things confuse me. How can I tell which sound devices Linux recognizes? I have three: an onboard chip, a USB audio interface (an M-Audio FastTrack), and a USB webcam that has a microphone. Do all of these things get recognized by Linux? Do they all register specifically as sound devices? Does each device have to have independent drivers for JACK, ALSA, PulseAudio, etc.? Is there a basic way I can test my device to make sure it has output? Is there a way I can monitor my devices to see if the software is actually using them?
Right now Amarok sound is audible, but Youtube sound isn't. Amarok is also running through my USB FastTrack instead of my onboard sound chip. Hydrogen refuses to start, presumably because I have JACK or Alsa or something configured wrong. I have no idea how to figure out the rhyme or reason for these things.
I realize I am asking several questions. I am not really hoping to get an answer for any specific one, but just trying to paint a picture of the general mayhem I am experiencing. I know the questions are supposed to be focused and I apologize but I feel like I'm at the end of my rope. I'm hoping there's some nice, well-written "Here's how you work the sound on Linux" article (or set of articles) I just can't find. I am slightly panicked only because there seems to be so little information available on JACK in general, even on the official JACK wiki. Please help!!