If your talking about the top of the line grado statement the original had an output of 0.8mv and the current version is 0.5mv. There is a "statement" series which covers the entire price range all having an output of 0.5mv. The "reference" series has outputs of 4.8mv.
The 0.5mv output needs a phono section gain of 55-60db to work well, usually found in phono sections with moving coil inputs. I suspect you have a moving magnet phono section which usally have gains in the 40db range and require a cart. output of 1.5mv or higher.
The 4.8mv output you mention is one of, if not the highest, gain available. Most "high output" moving coil cart.'s have gains in the 2-2.5 range. There are lots of nice high output cartridges available. Let us know what your actual phono section/cartridge situation is and will go from there.