I recently had to lay down a couple of quick guitar lines for a voiceover track I was working on (long story), and it turned out to be no big deal. When you need to add a little guitar to a digital track, and there are plenty of ways to do it (the worst way being the built-in microphone on your computer), but one of the easiest has to be using an Apogee JAM to directly throw the sound into the Garageband program of your Mac.
This has to be one of the simplest devices I have run into. When you open the box you fill find the JAM (made in the USA!) and USB, Apple 30-pin and Apple Lighting connectors. The JAM itself has a ¼-inch input, a US output, an LED and a gain control. The gain is easy to use: if the LED is green, you are ok, and if it is red, turn it down a little bit. There are no batteries involved, it is powered by whatever you plug it into, which would be your computer, iPhone, or iPad.
When plugging it into my computer or iPad, no set-up was needed, Garageband immediately recognized the JAM and I could start hacking around right away. Supposedly it will also work with Logic and Mainstage, but I do not have those so I could not verify if this is true. It is optimized for guitar and bass, and it did not have any trouble with any of my passive or active instruments; even the 18-volt preamps worked with no overloading. There is no mention in their literature about keyboards or mics, but I do not see why they would not work pretty well too.
This is a digital unit, and the sound is very good through all registers. There is no noise added to the singal, and it does a good job of delivering a clean signal to the device of your choice. By the way, the JAM gave me the opportunity to finally screw around with the amplifier emulations in Garageband, which is a fantastic way to lose all track of time!
At $99, the Apogee JAM is not the cheapest interface out there, and it is not even the best now that there the a newer product on the market – the more sophisticated Apogee JAM 96k (for $129). But it is simple and effective and mine is not going anywhere anytime soon. Check one out for yourself and see what you think!