Linda, you don't need to buy a special turntable to convert your vinyl. There's a product called Audacity which is available (free) from Sourceforge. With that, you can plug your ordinary turntable into your PC, using the appropriate leads, play your record to create a wave file and then export it as an MP3. I can't remember if you have to put it through your amp or not, but if you do (and I think that's the case) you can use your ordinary amp, too. It might sound a bit complicated but it's a doddle once you've set it up. Like you, I have a large vinyl collection, a lot of which consists of singles from the 60s and 70s. By using Audacity I've now got them, along with all my LPs, on my iPod and it didn't cost me anything other than time. Brill!
By the way, the software also does a reasonable job of eliminating the sound of scratches, too!
