Tokyo-based Sansui made a name for itself as a leading supplier of vintage amplifiers at a time when Japanese brands - among them Pioneer, Kenwood, Onkyo and Technics - were the most popular. Fighting for attention and street cred among hi-fi connoisseurs, Sansui introduced the 9090DB in 1976, hailing it as "one of the most technologically advanced amps on the market" in its sales brochure. A bold statement indeed, but this amplifier must have been special, because it could compete with models such as Pioneer's top-of-the-line SX-1250.

The Pioneer HPM-150 is a 4-way, 4-speaker, floor-standing bass-reflex system with tweeter and midrange level controls on the front panel. Produced in 1978. One of the best Pioneer speakers in those years.