First introduced in late-1971, this Panasonic RE-7750 receiver is from their "Series 44" line of 4-channel / quadraphonic / quadrasonic receivers and players.
The exciting new world of quadraphonic stereo surround sound was just taking off when Panasonic introduced a line of 4-channel products, including three different receivers (two with 8-track players built-in) and a quadraphonic turntable. Panasonic named the RE-7750 "The Whitney", and it originally retailed for $199.99. The Panasonic RE-7750 is an actual 4-channel receiver, not a pseudo-surround or enhanced stereo unit. It "plays everything: discrete, matrix, enhanced stereo, ordinary stereo, even monoraural" (per an actual Panasonic print ad from 1972).
The Panasonic RE-7750
has four separate volume slider knobs for left/right front & rear speakers, and is equipped with front and rear stereo 4-channel tape input on the rear. It also has a dedicated stereo phono input and one 2-channel stereo output. It also has a special DIN-like jack labeled "remote balance", which accepted a special remote control box that let you adjust the individual speaker volumes from the comfort of your favorite chair. Classic faux walnut wood grain finish, chrome accent, and green lighted tuning dial give it that unmistakable vintage Panasonic look. Entire unit measures 17 1/2 inches x 9 1/2 inches x 4 3/8 inches. The tuner works surprisingly well with no external antenna attached, and the Panasonic RE-7750 is actually a great little quad receiver with classic retro looks and reliability.