Ovation Guitar #69 Internal Research and Development Test Document

This is an internal Ovation Guitar Company research and development document tracking the acoustic testing and measurement history of guitar unit #69 (S/N 0069), Model #1687-7, from its initial construction in December 1976 through multiple evaluations in 1977. The document includes detailed bracing specifications, deflection measurements (RL, SN, K columns), and qualitative sound assessments by evaluators including references to 'Bill, CHK and Dadi.' Two frequency response charts (acoustic spectrum analyzer plots) are included, dated 8/23/77 and 12/1/77, showing the guitar's acoustic output in decibels across the full frequency range.