Guys, thanks for your comments and suggestions.
Altbrewer, I *think* that I have it working with the Duet, usinf the PV RIAA equalization. I'm still having trouble with the recording trigger - the recording stops when the music passes from a loud passage to a quiet one. I did send an email to Channel D, but their web site does state that support is for registered users. Fair enough, but why would I buy something that I cannot make work?
I think that the application is pretty good, but their documentation for v3 stinks. And you are correct, there are significant differences between the v2.3 and v3 interfaces that make the former documentation almost useless, except maybe as a concepts document.
Any other suggestions?