The method of steepest descents is applied to evaluate the impulse response of a number of identical buffered circuits in cascade. It is shown that exact results may be obtained by analogue computing. Approximate analytical expressions are obtained for various values of time, including the period of build-up. These are tested against two networks for which exact evaluation is possible. A cruder approximation valid near the build-up time is applied to predict suitable parameters for video-frequency compensating networks. These again are checked with known results.