| 摘要 |
PURPOSE:To obtain an inexpensive audio signal processing device of small and multi-function type by using a three-pole type stereophonic earphone jack, and so constituting the jack as to be capable of selectively changing a connection to an external additional device. CONSTITUTION:In the state wherein nothing is coupled to a threepole stereophonic earphone jack 2A, a low-frequency signal from a low-frequency amplifier 1 is outputted from a speaker 3 via mechanical contacts S1 and S2. When an earphone 17 as an additional device is connected, a two-pole type earphone plug 4b is coupled to the three-pole type stereophonic earphone jack 2A. On the other hand, a tone squelch 19, and an information receiving and displaying device as additional devices are connected, a three-pole type earphone plug 4a connected to each device is coupled to the three-pole type stereophonic earphone jack 2A. As a result, a low-frequency signal from the low-frequency amplifier 1 is inputted to the additional devices via a contact J1, and a signal from the additional devices is outputted from the speaker 3 via another contact J2. |
