I want to thank all
of you for the great replies. I am so frustrated with the lack of Linux Support.
I forgot to mention I also have a Behringer UCA-202....
The UCA-202 works out of the box for me. Due to the low input impedance (standard 600-ohm audio interface) you need a buffer/preamp of some sort. Usually a clean-type pedal can serve the purpose. For example, I have a Line6 echo pedal. Before I made a proper preamp, I set wet/dry all dry and simply use it to buffer the guitar input.
Stompboxes with active bypass are also a good bet. The Ibanez TS-series pedals are generally active bypass, so they will be buffering the signal when bypassed. The majority of stompboxes are active bypass.
Anyway, once you have something serving as a line driver/buffer then you only need the audio cables to adapt 1/4" Mono to an RCA. I usually put my guitar into the left channel and put a microphone in the right channel to use with the vocoder in Rakarrack.
I am an electronics hobbyist, so I have built my preamp into an Altoids tin, and that serves my needs.http://transmogrifox.webs.com/altoid1.jpghttp://transmogrifox.webs.com/altoid2.jpg
I'm not one who thinks 16-bit is bad quality audio (esp for guitar). Many of these 16 bit cards can achieve 90dB dynamic range, which is good enough for the girls I go with. The trick is to adjust the signal level going in so you're using maximum resolution without clipping. The UCA-202 has served me well.
If your Behringer mixer is one of the USB models it is likely it will work with Linux.
BTW -- for a guitarist you may be interested in GNUguitarINUX: http://gnuguitarinux.sourceforge.net/
I just tried out the v1.0RC today. It's an incredibly low-resource environment, thus leaving maximum processing power available for audio work. What's great about it is you can burn it to a USB stick and carry it around in your pocket. Then you can turn almost any computer into a guitar FX processor
. I think it's very slick.