That's a tough one. Unless you're grossly dissatisfied with the monos' sound, I would suggest you try a(n) active pre(s) to gauge the difference -- before you embark on mega$ changes.
Otherwise, I agree with Rhagen: big tube amps would be the norm. I would add, detailed, too.
Good luck!
Otherwise, I agree with Rhagen: big tube amps would be the norm. I would add, detailed, too.
Good luck!