|Audio Tape Digitisation Workflow
Inaccurate alignment of the record head of the original recording where the angle of the head gap varies from an exact vertical position relative to the tape produces a dramatic loss in high frequencies and phase distortions when played back with accurately aligned playback machines.
Adjust playback azimuth to optimum high frequency response (trained ears are essential). An oscilloscope or a real-time spectral analysis tool may be used to adjust for optimal high frequency response and phase coherence.
Operation manual of Studer tape recorders
John G. McKnight: Azimuth in a Magnetic Tape Recorder
Richard L. Hess: Azimuth - Hows and Whys