Do you just want to slow down recordings so you can learn parts? If so you can get Audacity recording software for free and it will do this and a lot more.

http://audacity.sourceforge.net/

http://download.cnet.com/Audacity/3000-2170_4-10058117.html

This would sure be easier than the days when I was learning fast horn parts like dixieland clarinet or bebop improvs. I had to take our reel-to-reel tape recorder and if it was recorded at 7 1/2 I could play it back at 3 3/4 to hear it half speed, but an octave lower, or to 1 1/8 (or some such fraction) and it would be twice as slow but two octaves lower.