As JD points out, the sound quality of analogue sources are seldom (if ever) what we're used to in this digital age. I've made quite a few digital copies of old analogue stuff, and I've always found that buying the music from iTunes (ACC) gives a far superior sound quality.
Not because the digital equipment weren't good enough, but because analogue sound reproduction is marred by noise, speed instability and other kinds of distortion.
You might make yourself deaf to this when listening to your old analogue gear -- but you'll sure hear it when you get the recordings into a computer and can compare it directly with digital originals...
If you've got unique material that's not available in digital formats, the USB phono boxes with line in from NAD or Pro-Ject will be fine. So will an inexpensive USB sound card, or even a decent built-in sound card.