Hi. Please can you confirm whether you issues were resolved? I realise this was an old posting but I have just purchased Wavepad and like you, I am transferring open reel tapes to my Mac vis a USB interface. I have set my audio settings and I am able to record without issue, I can also play back and hear my recordings, but no matter how hard I try, I can't get any sound while I'm recording which for my project is quite important. If you have managed to resolve this, I would be extremely grateful for any help you can off.
Many Thanks, Mick H