An example audio play circuit includes a power supply module, a power amplifier, a coupling capacitor, a load, and a plosive suppression circuit. An output terminal of the power amplifier is connected to a first terminal of the coupling capacitor and an output terminal of the plosive suppression circuit, a second terminal of the coupling capacitor is connected to the load, and an output terminal of the power supply module is connected to a power supply terminal of the power amplifier and a power supply terminal of the plosive suppression circuit. The power supply module is configured to provide a direct current power supply voltage for the power amplifier and the plosive suppression circuit. When the direct current power supply voltage rises to the first voltage threshold, the plosive suppression circuit connects the first terminal of the coupling capacitor to the ground terminal.

The present invention is a modular signal converting apparatus and method, and particularly, discloses a signal converting apparatus, which is modularized for playback of digital contents and is usable while being combined with another electric device.

The embodiments provide an apparatus for converting an audio signal, in which a left channel line and a right channel line connected to an amplification unit of an audio signal converting apparatus are covered with the ground and connected to a chassis of the audio signal converting apparatus, and a digital signal line and an analog signal line are disposed to be spaced apart from a substrate to improve crosstalk and remove noise.

An audio device includes: a processor configured to perform signal processing on the sound signal according to a value of a parameter; a display; a plurality of operating elements; a controller configured to: change the value of the parameter in accordance with an operation performed through any one of the plurality of operating elements; cause the display to display the value of the parameter; and write the value of the parameter in the current memory; and a detector. The controller is configured to: execute a first routine, which is uninterruptable by another routine, when the detector detects the malfunction; and cause, in the first routine, the display to display a first message without newly storing the value of the parameter; and mute, in the first routine, the processed signal in accordance with an operation performed through any one of the plurality of operating elements.

Embodiments provide a device for removing noise of a power source and an apparatus for converting an audio signal, which remove a noise component which comes from a power source terminal of an audio signal converting apparatus stepwise and transfer power to a converting unit and an amplification unit included in the audio signal converting apparatus from a power source terminal to remove power noise.

Systems and methods are provided for reducing the effects of an impedance mismatch between a communications system and a shared communications medium. A communication system, such as a transceiver within a cable modem, switches between various operating modes including a transmit mode, a receive mode, and a standby mode. The standby mode may be used while the transceiver is in an idle state between modes, such as while changing an amplifier gain states in between transmissions. While transitioning between modes, the impedance presented by the communications system can temporarily fluctuate causing unwanted signal reflections to propagate out of the communications system and on to the shared medium. Circuitry within the communications system, such as transmission circuitry including an adjustable attenuator, may be placed into a hybrid attenuation-isolation mode during the transition causing the magnitude of any unwanted signal reflections to be attenuated and reducing the impact on the shared medium.

A pop sound suppression method, an audio output circuit, and a terminal suppress a pop sound that is generated when an audio output circuit is in an alternating current (AC) coupling structure. The output circuit includes an output power amplifier, a common-mode voltage buffer, a reference voltage generation circuit, a powered-on pop sound suppression switch, and a common-mode switch. The powered-on pop sound suppression switch is configured to control, in a power-on process of the audio output circuit, a voltage level of an output node to be zero. The common-mode switch is configured to control, when a reference voltage level of the reference voltage generation circuit is zero, the voltage level of the output node to be equal to the reference level.

Embodiments described herein provide for detecting presence of an object in proximity to a playback device and responsively performing one or more operations. In an example implementation, a playback device detects, via a proximity detector of the playback device, presence of an object in proximity to the playback device. In response to detecting the presence of the object, the playback device performs one or more operations.

The present invention proposes an audio signal muting apparatus setting and adjusting a time for removing pop noise and muting an audio signal based on the set and adjusted timing. Further, the present invention proposes a digital signal converting apparatus for muting an analog audio signal based on a timing for removing pop noise when converting a digital audio signal into an analog audio signal in connection with an audio signal reproducing apparatus.

A class D amplifier receives and amplifies a differential analog signal which is then differentially integrated. Two pulse width modulators generate pulse signals corresponding to the differentially integrated analog signal and two power units generate output pulse signals. The outputs the power units are coupled to input terminals of integrators via a resistor feedback network. An analog output unit converts the pulse signals to an output analog signal. The differential integration circuitry implements a soft transition between mute/un-mute. In mute, the integrator output is fixed. During the soft transition, the PWM outputs change slowly from a fixed 50% duty cycle to a final value to ensure that no pop noise is present in the output as a result of mode change.