Vinyl to Digital: Software or USB Converter?


I'd like to digitize my vinyl to play via AIFF. The options are a) to use a phono preamp which outputs USB, or b) to run the preamp output directly into the Mac's audio input and digitize it with Roxio Spin Doctor. Any recommendations on which would produce higher quality recordings? If you recommend the software route, any suggestions besides Spin Doctor?
gordonmj
Audacity, which is free and easy-to-use, would also work very well for running from your preamp directly into the Mac.
Best quality would be achieved by using a good A/D converter, like the PSAudio or a Mytek etc.. The master clock is critically important here.

Steve N.
Empirical Audio
Thanks, all, for your suggestions. Steve N., it looks like PSAudio and Mytek only make D>A converters, not A>D (and frankly, even what they do make is a little out of my price range). Are there any A>D converters you'd recommend under $500? I know there are several available with built-in MM phono preamps, which would be acceptable, but not required.
Gordon - you are correct. I was thinking of the Ayre A/D converter. Good reviews.
Soon as I have the time to start converting some of my vinyl to digital a friend has the NagraVI A-D recorder I am going to try. First full project will be the Led Zeppelin 45 box set after some test records.