Description Product Description Perhaps the most revered vintage D-28s are the ones Martin created in 1937 with forward shifted hand-scalloped X-bracing, Adirondack red spruce soundboard and a 1-3/4" neck width. This addition to the Authentic series is a recreation of the original 1937 model offered with Madagascar rosewood back and sides. Martin's Vintage Tone System (VTS) is employed for the top and braces. The Martin Vintage Tone System (VTS) uses a unique recipe that is based on the historic torrefaction system. The VTS acts much like a time machine in which Martin can target certain time periods and age the top/braces to that era. This focused method allows Martin's craftsmen and women to recreate not only the pleasing visual aesthetics of a vintage guitar, but also reproduce the special tones previously reserved for vintage instruments.