" I am very happy with my LS-10
Mark, John: I'm sure that there are many happy LS-10 users out there.
But nothing that you wrote addresses the major issue for the OP: the line in requires a very loud signal. Sure, if you feed it with a line signal from your cassette deck, no biggie. But a 9V preamp in the field is a totally different story.
Read the OP again, and the links to Chris' and Guysonic's evaluation. LS-10 is not the
best line in recorder for unamplified soft acoustic music.