| 摘要 |
<p>PURPOSE:To obtain a desired voice output from one loudspeaker, by outputting from only a full band amplifying circuit, in a multi-amplifier consisting of the full band amplifying circuit and a narrow band amplifying circuit. CONSTITUTION:The first and second jacks 13, 23 for cutting off the first and second signals to the first and second loudspeakers 16a, 16b are provided. In this state, when plugs are not inserted into the jacks 13, 23, a signal amplified by a pre-amplifier 11 and a full band amplifying circuit 12 is applied to the internal loudspeaker 16a, and also is applied to the internal loudspeaker 16b through a volume 17, an LPF18 and a power amplifier 19. When a plug of an external loudspeaker 26a is inserted into the jack 13, a signal from the amplifying circuit 12 is applied only to the external loudspeaker 26a, and as for the loudspeaker 16b system, its electric circuit to the circuit 12 is cut off.</p> |
