A new experimental detector cluster for the TAIGA-IACT telescope has been developed. The cluster contains 28 pixels based on MicroFJ-60035 silicon photomultipliers, whose signal is digitized with an analog memory chip (switched capacitor array) DRS4 at a frequency of up to 5 GHz. The paper describes the device and the operation principles of the detector cluster, reveals the peculiarities encountered in the development process. Dark chamber tests of the cluster with a point source of short pulses of ultraviolet light have allowed us to obtain dependencies of the cluster conversion coefficient and the maximum value of the recorded signal on the overvoltage of the silicon detectors.