Thanks for your various replies.   Interestingly, the point about compression has come up in the Zoom users' forum, where I have also raised this puzzle. I am also grateful to see that Audacity is downloadable - I didn't know that. I'll try again.

And thanks, punkfolkrocker - I had wondered about cutting a one-off low-level disc for the pub. I have to be tactful with them... the pub manager is the singer on the blues album!!!