Both the Blue3 and Red3 use a four piece OTL cantilever that has a Grado specific diamond mounted on a brass bushing. The Red3 are hand selected from Blue3 production runs which meet higher test specifications. Approximately 10% of the run usually exhibits these specs and become a Red3.
Grado’s OTL, or optimized transmission line, technology provides an ideal transfer of signal from the surface of the LP to the generator of the system. This technology rejects unwanted resonances and lowers distortion preserving the fundamental and harmonic frequencies of the music. This also helps keep noise generated by the motor system in the cartridge to a minimum.
"The Grado Prestige Red is proof that one does not have to spend large amounts of money for good sound from a phono cartridge."
-James T. Frane / $ensible Sound magazine