From Ambrosia Software:
WireTap Studio is a professional audio recording, editing, and management solution, allowing you to manage and manipulate your audio with ease. Discretely record from a specific application, record all of your Mac system audio simultaneously, or even record from any hardware/line-in device of your choice. After recording, edit your clips with WireTap Studio's revolutionary and completely lossless editor. Lossless master recording technology enables you to edit your recorded audio without any loss of quality or content. Come back days, months, or even years later and undo the changes you've made. You can even take a file you mistakenly recorded at a lower quality and increase the quality at any time, without the need to re-record. Even better, patent-pending LivePreview(tm) technology enables you to preview your audio before you capture it, saving you lots of time and stress. No longer will you need to record multiple bitrates and formats and then compare them side by side. Change the bitrate, compression format, or even add Audio Unit effects, and hear the changes in real time.