I am very tempted to buy one as well. The only drawback I can see with old scopes is that they are big & heavy and they take up lots of room. Pretty much any scope is OK for audio as the bandwidths involved are so small
Whatever you buy, make sure it has two channels and that it comes with leads & probes.
Hs anyone used one of these USB scopes? Anyone who uses a Mac?
Nick Froome