| 摘要 |
Line and audio processors (2,3) are provided as part of an integrate circuit (1). During an initial period following energisation of the circuit a terminal (A) of the IC is connected with a terminal (F) of the line signal processor through a diode (D2). A line output stage (4) provides a supply voltage to terminal (C) of the IC. A second diode (D1) now turns on and the first diode (D2) becomes reverse biased to cut-off. Terminals (C,F) are interconnected to supply the live signal processor and an audio signal stage. The live output stage controls a change-over switch (6) to interconnect contacts (7,9). The resistor (11) now connected to the audio signal stage is the volume setting adjustable resistor. |
