In 1967 the 36-series tape recorders ended with the G36, and were superseded by the transistorised A77 with a servo-controlled direct drive capstan. Over 80,000 36-series recorders had been manufactured. The A77, of which more than 460,000 were built, was complemented by an integrated amplifier (A78) and FM tuner (A76). The start of the 1980s saw the introduction of the "B7xx" series of high fidelity components, which was in turn replaced by the B2xx series in the mid 1980s. The B2xx series was versatile (the B250 amplifier offering 10 signal inputs, each with automatic sensitivity calibration) and feature-rich, all components containing microprocessors. Contrastingly, the "H" line, with "H" standing for Human, went to the opposite extreme, with minimalist control interfaces: several "H" components having only three buttons.