Abstract: A system is provided for detecting and correcting signal distortion in a received digital signal which comprises a series of pulses whose parameters are defined by transitions in the amplitude of the signal pulses. The device of the invention includes components which sample the signal pulse values a predetermined number of times, a variable length shift register having a variable number of memory cells for selectively storing and retrieving the sampled signal values, a variable frequency clock and provision of synchronizing the reference clock with the sampled signal pulses.