Convention Paper
Distribution of the Phonograph Signal Rate of Change
AES Convention 62 · Paper 1448 · March 1979
Abstract
The distribution of the rate of change of the RIAA-corrected phonograph signal was measured. Thirteen recordings representing various kinds of music were used, including both processed and direct cut discs. The measurement was designed to give for each music sample the totalized time during which the signal rate of change exceeds a certain threshold value. The totalized times as a function of the threshold are presented in the range of 10 µs to 1 s for music samples, with a length of about 3 minutes each. Also, the peak voltages of the signal and the signal derivative were measured. The distribution of the signal rate of change is dependent on the music character giving the high content of a large rate of change-values for pop and brass-music, and lower values for certain classical and purely vocal music samples. The maximum rate for change varies from 5 to 110 V/ms and the maximum peak-to-peak voltage from 1 to 7 V in the output of the RIAA amplifier. The normalized value i.e. the maximum rate of change divided by the maximum peak-to-peak voltage, ranges from 3 to 25 V/Vms.
