| 摘要 |
PURPOSE:To record a discrimination signal between pieces of music on a magnetic tape when a noise reduction circuit is inserted, and by exercise switching control during reproduction, by a tape recorder wherein the noise reduction circuit is inserted and uninserted during recording and reproduction. CONSTITUTION:For noise reduction processing, changeover switches SW1a, SW1b and SW1c are placed at side NR. An audio signal is passed through an amplifier 2 and a recording equalizer amplifier 4 for the noise reduction processing. When a magnetic tape detector 16 detects a magnetic tape part to generate a time pulse by a monostable oscillator 18 through a logical circuit 17, an AND circuit 19 operates through a switch SW4 for discrimination signal generation. With the time pulse, a muting circuit is put in operation. Then, this time discrimination signal is recorded on a tape. In reproduction, the discrimination signal recorded on the tape is supplied to a switch changeover control circuit 26 through a filter 23 and a timer 24 to generate a signal there, holding the switch SW1b at the side NR continuously. |
