An apparatus, a signal processing circuit and a method for reproducing data stored on a disc to prevent a buffer memory from going overflow/underflow. Writing information data read from the disc to the buffer memory is performed in synchronism with a reproduction stage clock signal, and reading from the buffer memory is in synchronism with a signal processing stage clock. The signal processing stage clock for reading information data from the buffer memory is changed in accordance with the amount of information data stored in the buffer memory for preventing interruptions in data reproduction.