This paper deals with the application of the simulated inductor in the continuous-time allpass filters and group delay sensitivity analysis of the realized filter. The realization of filter pair based on the LCR resonator circuits employs a single generalized grounded impedance converter, which can be implemented with only one operational amplifier. A group delay sensitivity measure can be useful for comparison of the second order allpass filter cells, used for continuous-time filter pair design. It can be related to the well known pole Q factor- and pole frequency-sensitivities by a simple analytic expression. A design procedure is developed in which tuning can be achieved by trimming only resistors.