Excellent, Cheap Mike Preamp for Computer Recording

Macs come with line inputs via their 3.5 mm input jack. This means that you can't connect microphones to a Mac. Either you buy a mike preamp, or you buy an external audio interface with a mike preamp built in. Inexpensive audio interfaces usually cut corners, particularly on the mike preamp. My yamaha usb mixer had that problem -- the preamps were adequate, but noisy.

ART makes an inexpensive tube based mike preamp that periodically goes on sale. You can plug in either unbalanced or balanced inputs -- such as a guitar, or a professional microphone. It has a simple limiter, phantom power for microphones that require a power source. It sounds much better than it's $30.00 price. I have used it with a griffin iMic for a while now to record voiceovers with a Shure SM57 microphone. It is bare bones to be sure, but it works well enough. It is not pristine -- but I like the simplicity and compactness. I can unplug the mike, and plug my guitar in. I can even overdrive the preamp a little bit to give the guitar some bite.