Realistic Quatravox
I have a couple of these Realistic Quatravox units from the 1970s. They convert two-channel stereo into four-channel for a surround sound effect. When these units were out quadraphonic sound was the latest fad, Radio Shack marketed these as a low cost alternative to get into four-channel sound. They require no external power, just a simple circuit with switches and resistors.
Realistic Quatravox
I have a couple of these Realistic Quatravox units from the 1970s. They convert two-channel stereo into four-channel for a surround sound effect. When these units were out quadraphonic sound was the latest fad, Radio Shack marketed these as a low cost alternative to get into four-channel sound. They require no external power, just a simple circuit with switches and resistors.