Sound recording quality control during playback from master tape - stores signal at certain tape part and same signal compared with it during subsequent playing

摘要

Sound signals are recorded on a tape and signal levels are compared during first playback with those during subsequent playbacks. During first playing back of tracks on a master tape, a reference (nominal) signal in the upper frequency range of the master signal is scanned at a certain point of the tape and stored. During subsequent playing back the same part of the tape is scanned again and the actual signal level is compared with the nominal level. When a specified level difference is detected, a control and/or switching device is operated.