I had a JR 525 in my system briefly, replacing a monster McCormack DNA-500. I paired it with a Modwright-LS 36.5 preamp. It sounded pleasant enough but I felt it was lacking in dynamics, presence and oomph. I then bought a used JR Continuum S2 here on A'gon and used that in place of the 525/MW and McCormack/MW combos. Much, much better. I sold the 525, McCormack and Modwright -- all great units, but the Continuum sounded at least as good as the McCormack-MW combo and I thought it was appreciably better than the 525-MW combo.
