Modulus 3A has more than enough gain for a Denon DL103R which is a pretty low output cartridge. I jave the John Curl MC upgrade boards and it sounds very, very good with the 103R.
Mid level gain cartridges should work fine with the moving magnet tubed stage. Only the very lowest output cartridges require the additional MC step up.
Mid level gain cartridges should work fine with the moving magnet tubed stage. Only the very lowest output cartridges require the additional MC step up.