Starting in 1958, the 6121 Chet Atkins solid-body was redesigned with Gretsch's Filter'tron humbuckers replacing the original DeArmond single coil pickups. The control circuit was also updated, moving from 1957's 3x1 knob layout to a 2x1 layout, and adding a tone switch on the upper bout. Aesthetically, the 1958 model retained the late '57 "thumbprint" inlays, but lost the G brand on the upper bout. The 6121 was redesigned again late in 1961, alongside most of Gretsch's catalog, moving from a single cutaway body to a double cutaway body.