Sigma DR-28 Dreadnought Acoustic Guitar The Sigma DR-28 is a beautiful steel-stringed guitar which is lend towards the design of traditional american acoustics. Besides a solid top of sitka spruce, the Sigma DR-28 features Indian rosewood back and sides which - combined with the white body bindings - lead to a very distinctive look. The sound of the Sigma DR-28 acoustic guitar offers a warm overall character without getting dull at any time. As the mahogany neck features a rosewood fingerboard, a soft attack is added, so every single note stays perfectly defined while strumming chords. The Grover tuners and the flawless craftmanship makes the Sigma DR-28 to a valuable instrument.