The Griffin Technology’s iMic is basically an external USB sound card, allowing you to connect microphones or other line-level inputs, as well as providing line-level outputs to headphones or powered speakers. My MacBook Air doesn’t have any audio inputs, apart from the built-in microphone. The latter, of course, is not useful when you want to record audio from a line input.
Technically, the only 3.5mm jack on the MacBook Air can be used as a microphone input, but only through the iPhone-style combo earphone/microphone. If you need to bring in any other type of audio sources, it will be necessary to use a USB audio interface.
The iMic is relatively inexpensive. There are two 3.5mm jacks: one for input and the other for output. The input can be used from microphones or line-level signals, selectable via a switch on the side.
This is a very inexpensive gadget, so don’t expect too much out of it in terms of audio quality. The DAC (digital analog converter) is spec’ed for 48kHz 16-bit 2-channel audio.
Sound output from the iMic is decent. There is definitely much less hiss when compared with the built-in output of the MacBook Air. But otherwise, I would not say its overall audio quality was better or worse. It is no match for a proper USB DAC (which, of course, would have cost a lot more), not even relatively inexpensive ones such as the Fiio E10.
There is no microphone input (apart from the built-in microphone) to the MacBook Air, so I couldn’t compare the iMic with it. I was not impressed when I plugged in a standard PC-type microphone. There was far too much noise, so bad that I’d rather be using the built-in microphone of the MacBook Air. I’m not sure if things would be better had I used a better quality microphone.
I’ve not tested the line-level input. I’ll update this post when I do that.
There are no drivers to install. Just plug in the iMic and start playing. Simple, as it should be.