The OB-B is the latest development in the evolution of Oberheim synthesizers. The design philosophy behind it was to take all of the feature3 of the OB-Xa, add as many new features as were economically feasable, and redesign all of the circuitry for increased reliability and lower cost. The result is a synthesizer with 90 fewer calibrations and 11 less circuit boards, and with many of the remaining calibrations microprocessor assisted. The circuitry and the trimmers that were eliminated have been replaced with software functions in the microprocessor which simulate the replaced hardware. Some of these functions are explained below.