Abstract: The optimum processing of magnetically or optically recorded data to recover recorded data bits and clocking information should include apparatus to compensate for variations in media velocity during writing and reading of the media. The adaptive velocity compensation circuit accomplishes this result by sampling the media velocity and comparing the sample to a reference velocity usng a digital tachometer. The result of this comparison is used to control a variable pulsewidth single shot which adjusts the operation of a phase locked loop phase detector to match the velocity of the moving media.