I have a few old recordings of class lectures on cassette tape that I really need to clean up. Does anyone know of any free or cheap denoise programs? Here's what I've already tried or passed over or cost reasons so far. The Waves bundle demo requires an iLok which I don't have. Soundsoap is $99, way more than I'd be willing to spend to do this one thing. Garageband "vocal enhancer" effect, it half worked but it only has presets for Apple microphones, not tape recordings or other noisy sources. Any ideas?