Different makes/models of deck have varying analog input characteristics so what works well with one may or may not work well with a different model.
A post I think to recall of one user's experience with LS-10
LINE input is it required
a much higher input signal that most low costing preamplifiers running on 9 volt batteries supply, so while working well with one model of deck, a certain external preamplifier will disappoint owners trying same into LS-10.
ONLY by doing bench input characteristics measurements of each model recorder and posting these results
in a clear manner will anyone know for sure what is likely to compatible with LS-10 model of deck, unless resorting to the trial/error of different mic/preamp gear combinations working different type venues.
While I've heard enough about LA-10 to not want to own one, if some kind person
sometime sends me a loaner LS-10 for testing purpose, then
we will know what might work OK with some certainty.
Or we can continue as usual of not knowing short of just trying stuff out under different live sound purposes
See my tips page with links to tech reviews and threads discussing various old/new deck models at:
www.sonicstudios.com/tips.htm.