I had the chance to try out an iRig Keys today in my classes. One of my students has a parent who tests and suggests merchandise–tech merchandise–to a major retailer. So my student often gets to bring tech toys to school that aren't even on the marketplace yet. He had mentioned that he has an iRig Keys, and offered to bring it to school to let me try it out. That happened today.
Setting up the iRig Keys was very simple…there are two different cables and two different ports. One is a USB port (mini? micro?) and the other connects to an iOS device. The keyboard draws power from the iPad (unlike the M-Audio Keystation 49i keyboards we bought in 2009 that DO NOT work with iPads), and a light on the Keys shows that you are accessing iOS. The iPad is Core-MIDI compliant, so the keyboard is simply tapping into that functionality.
Once you are in a Core-MIDI program, such as GarageBand, the keyboard “just works.” The keys are small–the entire unit isn't much longer than 3/4 of a “normal” piano keyboard, but it is extremely light and works well. The keys are not weighted, so the keyboard has a feel of a cheap digital keyboard. But it works.
I used the keyboard for warm-ups and throughout a rehearsal, (via GarageBand) both patching my iPad through my digital grand piano (audio in) and via mirroring through Reflection. As you would expect, there is a lag through mirroring, but no noticeable lag through local audio out.
The biggest problem with the iRig Keys is the connector cable which is a 30-pin cable…and the iPhone 5 and iPad Mini and iPad 4th Generation–and the iRig Keys website doesn't seem to indicate that a new cable is coming–and I'm not sure I would trust the 30-pin to 9-pin adapter for Core-MIDI functionality.
The biggest positives for this keyboard are that it works with iOS, it is small and ultra-portable, and that it can serve as a USB keyboard as well as a iOS keyboard.