| 摘要 |
PURPOSE:To rationalize the setting of an attenuator, by using a linear codec for every channel and using a digital compander common to a package after the linear codec. CONSTITUTION:A linear codec 3 consisting of a filter 4 and an A/D converter 5 is used for every channel CH of a voice channel CH board, and the sound signal is converted to a digital signal to multiplex the signal. A digital compander 8 common to the package is connected after the linear codec 3, and for example, one sample is converted to 8 bits. An ROM is used as the compander 8; and when a linear bit input is converted to a companded 8-bit PCM, a level is set accurately in each package only by using a prescribed ROM, and the attenuator used in every CH is adjusted in one place, and therefore, the adjustment is rationalized. |
