| 摘要 |
<p>PURPOSE:To use different kinds of noise reducing circuit to detect a no-signal part of a tape where sounds are already recorded, by switching a circuit so that the input level inputted to an inter-music space detecting circuit is constant in accordance with the selection of a noise reducing circuit. CONSTITUTION:The output of a reproducing head 1 is amplified by a regenerative equalizer amplifier 2 and is supplied to a fixed contacts 2C of an NR (noise reducing circuit) selecting switch S2 and input terminals of NRs 3 and 4, and also to an inter-music space detecting circuit 6 through a resistance R3. The inter-music space detecting circuit 6 includes a level detector, and its detection level is constant. The output selected by the NR selecting switch S2 is amplified by an output amplifier 5 and is supplied to an output terminal 8. When a level setting switch S1 is set to a contact 1a, the output of the regenerative equalizer amplifier 2 is divided by resistances R3 and R1 and is inputted to the inter- music part detecting circuit 6; and when the switch S1 is set to a contact 1b, the output is divided by resistances R3 and R2; and when the switch S2 is set to a contact 1c, the voltage divided by resistances R3 and R2 is inputted to the inter-music space detecting circuit 6, thus controlling a tape driving controller 7.</p> |
