Hello JAM,
My LS-16 Mk-II was a line stage only, as I believe the LS-25 Mk-II is. There is no direct phono input, so you will need a phono pre-amp. Audio Research produces a couple of models, if I recall - priced from moderately expensive to very expensive.
There are lots of other choices, however, from a couple of hundred dollars to many thousands.
Hope this helps and isn't too disappointing.
Regards,
RMR