I plug my guitar directly into my mac, via a
handy little usb device called the GuitarPlug.
Unfortunately, DVForge, makers of the GuitarPlug and MicPlug have
since gone out of business. Non-the-less they made amazing
products. Thanks to the GuitarPlug, I can plug my guitar, or microphones
directly into my MacBook
The Instruments
I currently plug three different instruments into my mac. I have an
m-audio 49e keyboard, connected over USB, through a
hub. I also plug my acoustic-electric Cascade
DC-25 guitar into my mac. Occasionally, I'll plug in a Hohner Blues Blaster 1490 or Egg-Static Harp
Mic using a JamPlug, iallowing me to record music from my
Lee
Oskar harmonicas. I also use a Behringer C3 microphone, when I'm recording
vocals.
The Setup
I plug in an Edirol FA-66 over firewire, into my MacBook. The
Cascade is plugged in over quarter-inch cable, into port #1, while
the Behringer is plugged into Port #2. The m-audio is plugged in
over USB, along with a simple trackball. This gives me the
flexibility to record guitar, vocals, and pretty much mix up
anything I want using the keyboard.