The dock connector provides a higher quality connection with less crosstalk than the headphone jack. Sonoma WireWorks already had a dock connector guitar interface, the GuitarJack, but it only worked on the iPhone 3G and 3Gs as well as the 2nd and 3rd generation iPod Touch. A new version, the Guitar Jack Model 2, will work with iPhone 4 and 4th generation iPod Touch, but has not yet been released.
A little bigger than a Bic lighter, the Apogee Jam has a clean and simple design, and a 1/4-inch input on the bottom lets you connect your electric guitar or bass using a standard instrument cable. A connector on the top allows you to connect one of two included cables: a 1 meter USB 2.0 cable that connects to your Mac or a 0.5 meter cable that connects to your iPhone or iPad's dock. A gain slider on the side of the Jam lets you easily adjust your input level, while a small multicolor LED flashes red if your level is too high, green when connected and ready to play, or blue if connected to your iOS device or Mac, but not ready to play. The Jam is bus-powered, so no battery or external power is required.
I was able to plug the Apogee Jam into both an iPad and a MacBook Pro and start playing without installing any drivers. While Apogee states that the Jam was designed to work with GarageBand, I was able to use it with a number of iOS apps, including AmpKit, GuitarTone, GuitarToolkit, and 4Track.
IK Multimedia's AmpliTube apps did not work with the Jam. On the Mac, I was able to use the Jam to record to Logic as well as GarageBand. By adjusting the gain using the Jam's slider control and the noise cancellation feature of GarageBand, I was able to get clear and crisp clean tones as well as crunchy distorted sounds.
Compared to other iPad guitar inputs I've used, like Griffin's GuitarConnect Cable and IK Mulitimedia's iRig, the Jam had the clearest sound. The Griffin is too overdriven and could benefit from a gain control knob.The iRig sounds better than the Griffin, but there's a little noise in clean tones. Neither the Griffin or iRig can plug into your Mac.
With its ability to plug into both your iOS device or Mac, the Apogee Jam is a simple to use, high quality guitar interface. It costs considerably more than available headphone jack adapters, but its clean clear signal and versatility make it a great little guitar gadget.