All Grado cartridges now use a derivation of the moving iron principle which feature patented Optimized Transmission Line cantilever technology, Pivoted Fixed Axial Stylus-Generator Module, and Grado's Flux-Bridger Generator System.

Grado's OTL provides an ideal transfer of the signal from point to point, e.g., stylus to cantilever to magnet to coils, etc. This has been achieved by eliminating resonance at each of these key junctions. The transmission line cantilever consists of separate sections that are telescoped into each other. All sections are made of different alloys, some sections hollow, other sections solid. These sections are bonded together with materials that act as dampers, and are coated with a black proprietary material which controls and absorbs resonances that travel on the surface of the cantilever (known as skin effects). The OTL stylus/cantilever design will make your records sound quieter, improve the height, width, and depth of the soundstage, and offer more detail than previously obtainable. Cartridge Holography does exist...and that is what Grado's OTL technology is all about, more performance.