Wow - what a wonderful and cheap piece of software I've found for recording straight from your Technics keyboard into your computer and producing an MP3 file - see:
http://www.polderbits.com/ If I could work out how to download you a sample of what it has achieved for me I'd do so...and they let you use the full software for 14 days free as a demo of what it can do...no I don't work for them; I just think it's brilliant.
Roger M