Tone control of the operational type
First Claim
1. A tone control circuit for modifying an audio signal comprising:
- an input terminal;
an output terminal;
means for directly passing said audio signal from said input terminal to said output terminal;
modification means for modifying said audio signal to produce a boost or attenuation signal corresponding to at least a portion of the frequency spectrum of said audio signal;
said means for directly passing said audio signal further including means for adding or subtracting said boost or attenuation signal to said audio signal, only when desired, to boost or attenuate the portion of said frequency spectrum selected by said modification means.
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Accused Products
Abstract
A tone control circuit for use in audio equipments includes an attenuating high pass filter (typically, a CR filter), an attenuating low pass filter, a boosting high pass filter, a boosting low pass filter and at least an operational amplifier for tone control. The high pass filters extract a treble component from an audio input signal for emphasizing or attenuating treble response, whereas the low pass filter extract a bass component of the audio input signal for emphasizing or attenuating bass response. The mid-range component of the audio input signal prevented from entering the filters by virtue of a bypass circuit interposed between a source of the audio input signal and the operational amplifier.
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Citations
9 Claims
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1. A tone control circuit for modifying an audio signal comprising:
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an input terminal; an output terminal; means for directly passing said audio signal from said input terminal to said output terminal; modification means for modifying said audio signal to produce a boost or attenuation signal corresponding to at least a portion of the frequency spectrum of said audio signal; said means for directly passing said audio signal further including means for adding or subtracting said boost or attenuation signal to said audio signal, only when desired, to boost or attenuate the portion of said frequency spectrum selected by said modification means. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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Specification