In case you're looking for a decent audio interface that works with Pd under Linux, you might consider the Mackie Blackjack. To my surprise, it worked out of the box in Debian Squeeze (Linux kernel 2.6.32 and 2.6.33).
The Mackie Blackjack is 2 channel with combined line / hi-z instrument / phantom-powered mic inputs, balanced jack outs plus headphone out with separate volume control. All pots and switches on top, very convenient on-stage form factor.
I use this interface with an Audio Technica ATM 33 condenser mic. Signal-to-noise ratio is excellent indeed.
The only gripe I have is about the build. Not really 'like a tank', as claimed by Mackie. Yes, the steel box will endure all abuse, but the plastic-shaft pots supported by nothing else than the print should be treated like a baby rather. Well I love it enough to do so.