| 摘要 |
PROBLEM TO BE SOLVED: To provide the tone control mechanism for an on-vehicle audio system where tone control is brought into an optimal preset state automatically through the selection of plural audio signal sources. SOLUTION: A control amplifier 10 is a tone control device that consists of a selector switch 1 for input signals IN1,..., Inn of plural audio signal sources, a sound volume adjustment volume control circuit 2, a balance control circuit 3, a tone control circuit 4, and an output amplifier 5 and also with a preset memory 7 that stores setting of a variable resistor for bass adjustment (BASS) and presetting of a variable resistor for treble adjustment (TREBLE) in the tone control circuit 4, and a control CPU 8 controlling them. When a selector switch 1 is switched, the CPU 8 reads data in a preset state of an audio signal source selected from the preset memory 7 and controls the tone control circuit 4 accordingly. |
