The link is to just the ASIO dll file for foobar. I don't have the actual program, though it shouldn't be that hard to find.
I have used SoX for de-emphasizing old Japanese CDs that used pre-emphasis, and I don't think it's the most transparent method available. I think it might be adding a bit too much EQ below 16 KHz. And the imaging seems to collapse a little after running it through SoX. The only other de-emphasis EQ I've tried is the one in foobar, by manually setting the EQ. I need to try another wav editing program since I'm now using the SB.