| 摘要 |
<p>PURPOSE:To raise a tone quality, by sounding through a loud-speaker both a signal from an audio frequency full band amplifier and a signal from a narrow band amplifier. CONSTITUTION:In case of a state that plugs are not inserted into jacks 13, 23, a signal amplified by a pre-amplifier 11 and an audio frequency full band amplifier 12 is applied to the first loudspeaker 16a, and also is applied to the second loudspeaker 16b through a volume 17, an LPF18 and a power amplifier 19. An output of the loudspeaker 16a becomes a frequency characteristic extending over the full band, and an input limited by the LPF18 is provided to the loudspeaker 16b, therefore, its output becomes a frequency characteristic of the narrow band.</p> |
