IMHO, that is a very crude way to get surround sound. While reverb was always a cool effect when added to electric guitar to use for surround produces an effect that could hardly be called hifi! I had an amplifier "Sears Electronics" that had a built in reverb. Those early units used a spring for delay (as does the RA-700), as I said a very cool effect when added to a guitar but very artificial added to recorded music.
As quad faded companies came out with "Bucket Brigade" type delay circuits. They were meant to add reverb to stereo, also a waste of time IMHO they didn't seem to last very long in the marketplace. Digital circuits also appeared, perhaps producing better sound quality but still the entire premise is flawed!