TEAC A-420, made in 1976 in Japan, was a successor of the most unusual deck A-400 crafted by TEAC one year before. The engineers at TEAC ensured operational efficiency and user-friendliness by grouping search controls independently, based on their extensive experience with data recorders and analog computing. A notable characteristic that distinguished the A-400 series was the absence of a 'RECORD' button. The Play and Record buttons danced on their own, easily activated with a deft turn of a knob. A small delay, a suspenseful moment before the record position, protected from unintentional removal, an intelligent move on the part of the engineers. Convenience was integrated into the A-400 series design from the ground up, not treated as an afterthought. Light-filled, front-loading pockets held cassettes in place so both spools could be seen. A simple choreography was used to eject a cassette: a slight raise at a 45° angle made for easy handling. The motor and drive system of the A-400 series was its key component. The best TEAC created a frequency-generated feedback control DC servo motor that achieved the highest speed accuracy while almost eliminating wow and flutter—it is only 0.08% or better. With its High-Density Ferrite Heads, which preserve distortion-free recording even at the highest frequencies, the A-400 ruled the audio fidelity scene. Although the A-400 series cannot be regarded as high-end, the CrO2 tape has an overall frequency response of 30 to 16,000 Hz. The A-400 series promises crystal-clear audio, reduced electromagnetic transmission loss, and less bias current requirements. However, the design of the A-400 series—a blend of practicality and style—was its most endearing feature. Its minimalist canvas front panel gracefully encouraged incorporation into any stereo system.
