NEW FACTORS IN PHONOGRAPH PREAMPLIFIER DESIGN
Tomlinson Holman · Journal of the Audio Engineering Society · 1976
INTRODUCTION: The normally quoted specifications of a phonograph preamplifier, such as frequency response, noise, and distortion, are of limited usefulness in ultimately determining how a preamplifier will sound. This is due to a variety of factors: for example, 1) no conventional test measures performance under transient conditions; 2) test results (with the exception of some noise measurements) are not weighted for human perception or annoyance value; and 3) the response to signals out of the audio pass band may affect in-band performance through intermodulation in the preamplifier or, more likely, later in the system. The measurement environment consisting of oscillators, meters, etc., represents a gross simplification of the real-world conditions in which the preamplifier operates. It is therefore not surprising that conventional measurements have low correlation