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Compatible Discrete 4
Compatible Discrete 4, also known as Quadradisc or CD-4 (not to be confused with compact disc) was a discrete four-channel quadraphonic system for phonograph records. The system was created by JVC and RCA in 1971 and introduced in May 1972. Hundreds of recordings using this technology were released on LP during the 1970s.
Other major record companies who adopted this format include A&M, Arista, Atlantic, Capricorn, Elektra, Fantasy, Nonesuch, Reprise and Warner Bros.
This was the only discrete quadraphonic phonograph record system to gain major industry acceptance. A competing system, UD-4, was later introduced by Denon (Nippon Columbia).
In discrete quadraphonic systems, all four channels remain fully independent of each other throughout the entire recording and reproduction chain. There is no intermingling of channels as is done in matrix decoder 4-channel systems such as Stereo Quadraphonic (SQ) and QS Regular Matrix.
Though CD-4 and other quadraphonic technologies were not widely accepted by the public, CD-4 was responsible for major improvements in stereo phonograph technology. These improvements included phono cartridges with higher compliance, lower distortion levels, wider frequency range, and new vinyl compounds for records. Such new compounds included JVC's "Supervinyl", which was more durable than conventional materials, and Q-540, which was highly anti-static.
Successful CD-4 playback in 4 channels requires a phono cartridge that can reproduce high frequency range carrier signals that extend well beyond normal human hearing. CD-4 cartridges are more critical in set-up requirements than those used for stereo records and for UD-4. This is because stereo records do not have carrier signals and the frequency of the carrier signals used in CD-4 are higher than those found in the UD-4 system.
Phono cartridges with very high-frequency range were rare in the 1970s but became much more common in later years. Only through the use of an elliptical tip stylus is the cartridge able to accurately reproduce the necessary extended range. This stylus is usually marketed as a Shibata or line contact type. By contrast, a standard conical or cone shape stylus has less contact area with the record groove.
CD-4 playback in 4 channels also usually requires a specialized CD-4 demodulator. Such demodulators have not been sold commercially since the 1970s, but today software decoding is also possible. Hardware decoders were often sold as independent components. However, some audio receivers and/or amplifiers built in the 1970s included the CD-4 demodulator as a built-in feature, along with FM radio and amplifier circuitry.
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Compatible Discrete 4 AI simulator
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Compatible Discrete 4
Compatible Discrete 4, also known as Quadradisc or CD-4 (not to be confused with compact disc) was a discrete four-channel quadraphonic system for phonograph records. The system was created by JVC and RCA in 1971 and introduced in May 1972. Hundreds of recordings using this technology were released on LP during the 1970s.
Other major record companies who adopted this format include A&M, Arista, Atlantic, Capricorn, Elektra, Fantasy, Nonesuch, Reprise and Warner Bros.
This was the only discrete quadraphonic phonograph record system to gain major industry acceptance. A competing system, UD-4, was later introduced by Denon (Nippon Columbia).
In discrete quadraphonic systems, all four channels remain fully independent of each other throughout the entire recording and reproduction chain. There is no intermingling of channels as is done in matrix decoder 4-channel systems such as Stereo Quadraphonic (SQ) and QS Regular Matrix.
Though CD-4 and other quadraphonic technologies were not widely accepted by the public, CD-4 was responsible for major improvements in stereo phonograph technology. These improvements included phono cartridges with higher compliance, lower distortion levels, wider frequency range, and new vinyl compounds for records. Such new compounds included JVC's "Supervinyl", which was more durable than conventional materials, and Q-540, which was highly anti-static.
Successful CD-4 playback in 4 channels requires a phono cartridge that can reproduce high frequency range carrier signals that extend well beyond normal human hearing. CD-4 cartridges are more critical in set-up requirements than those used for stereo records and for UD-4. This is because stereo records do not have carrier signals and the frequency of the carrier signals used in CD-4 are higher than those found in the UD-4 system.
Phono cartridges with very high-frequency range were rare in the 1970s but became much more common in later years. Only through the use of an elliptical tip stylus is the cartridge able to accurately reproduce the necessary extended range. This stylus is usually marketed as a Shibata or line contact type. By contrast, a standard conical or cone shape stylus has less contact area with the record groove.
CD-4 playback in 4 channels also usually requires a specialized CD-4 demodulator. Such demodulators have not been sold commercially since the 1970s, but today software decoding is also possible. Hardware decoders were often sold as independent components. However, some audio receivers and/or amplifiers built in the 1970s included the CD-4 demodulator as a built-in feature, along with FM radio and amplifier circuitry.