|
| US3958085 | 6. Mai 1974 | 18. Mai 1976 | The Magnavox Company | Compatible 4-2-4 encoding-decoding system |
| US4002835 | 6. Juni 1975 | 11. Jan. 1977 | | Multi-channel decoding circuit for two-channel audio systems |
| US4132859 | 2. Dez. 1977 | 2. Jan. 1979 | | Sound reproducing apparatus |
| US4251685 | 3. Jan. 1974 | 17. Febr. 1981 | National Research Development Corporation | Reproduction of sound |
