An embodiment of a voltage regulator includes a pass device, a feedback circuit, and an operational amplifier. A method of making a core insert for a light guide plate is also provided. The peroxide is preferably an organic peroxide. The tub is formed of a clear, ultraviolet light transmitting plastic. The method and apparatus may be particularly adapted to processing sonic data to measure formation slowness in a borehole. The DMS filter is connected in a symmetrical manner to a housing using connection pads or connection pins in order to produce an axis-symmetrical connection layout.