Ovation Guitar #26 Internal R&D Testing and Acoustic Frequency Response Documentation

This is an internal Ovation research and development document from 1975-1976 detailing the construction specifications and acoustic testing of experimental guitar prototype #26 and its variants (#26-1 through #26-4). The document includes detailed construction notes such as waffle top dimensions, brace weights, bridge measurements, and deflection readings (RL, SN, K, FF columns). Four frequency response charts (spanning approximately 30 Hz to 9397 Hz) for guitar #26-3 are included, dated from March 15 to April 18, 1976, with handwritten annotations noting sound quality assessments including a comparison to guitar #28-5 and comments from players including 'J. Messina.'