46 results about "Headphone amplifier" patented technology

A method of powering an audio output device of a computer system, by determining whether a passive or active audio output device is connected to an audio output jack of the computer system and, based on this determination, providing an appropriate power level to the audio output jack. For example, if the determination is made that a passive audio output device is connected to the audio output jack, then a 3-watt power signal is applied to the audio output jack, but if the determination is made that an active audio output device is connected to the audio output jack, then a ¼-watt power signal is applied to the audio output jack. The type of audio output device present may be determined by sensing an impedance at the audio output jack. This sensing may be performed by comparing a load voltage associated with the impedance to a reference voltage. The output of a switch device (multiplexer) having a first input from an AC97 audio codec and headphone amplifier and a second input from a passive speaker amplifier is selectively controlled by the sensing circuit.

A class G headphone amplifier circuit with improved power efficiency and low EMI. It may use an automatic signal level detector to detect the signal level of incoming signals and determine positive and negative power supplies for headphone amplifiers accordingly. A voltage generator may generate pairs of differential output voltages at a plurality of amplitude steps, and supply to headphone amplifiers the pair with the amplitude determined by the automatic signal level detector. As a result, headphone amplifiers are biased according to the input signal level, and the multiple voltage rails may improve power efficiency and avoid clipping.

A compact portable stereo headphone amplifier system for use with a conventional stereo audio source, such as a cassette or compact disc player, in which components are located on both sides of a circuit board and in which left channel components and right channel components are located on opposite sides of the circuit board thereby providing a compact unit.

A headset is provided including a first earpiece having a first earphone speaker and external speaker; a second earpiece having a second earphone speaker and external speaker; a controller with at least three operational modes, the controller including a power switch; a speaker switch; an earphone amplifier circuit; a speaker amplifier circuit; and a power source; the power source being positioned within the first or second earpiece; the input signal routed directly to the earphone speakers when the power switch is in an off position, the input signal routed through the earphone amplifier circuit to the earphone speakers when the power switch is in an on position and the speaker switch is in an internal earpiece position, and the input signal routed through the speaker amplifier circuit to the external speakers when the power switch is in the on position and the speaker switch is in an external speaker position.

The invention discloses a portable headphone amplifier casing for improving bandage stability. The portable headphone amplifier casing includes a casing body, first fixing grooves which are mutually symmetrically distributed are formed in the upper and lower ends of one side of the bottom of the casing, clamping plates are disposed in the first fixing grooves, the inner side of each first fixing groove is provided with a second fixing groove communicated with the first fixing groove, a first rotating wheel and a second rotating wheel which are symmetrically distributed are disposed in each second fixing groove, the first rotating wheel is connected with the second rotating wheel through a fixing belt, one side of the fixing belt is connected with the inner side of the clamping plate, the second rotating wheels are connected with a rotating shaft in the form of gear meshing, the upper end of the bottom of the casing is provided with a first adjusting groove, and an adjusting gear is arranged in the first adjusting groove. The other side of the bottom of the casing is provided with a first clamping groove clamped with the clamping plate, and the joint of the fixing belt and the clamping plate is provided with an elastic belt. The inner side of the fixing belt is provided with anti-sliding rubber, the anti-sliding rubber is distributed in a segmented mode, and the length of the anti-sliding rubber is equal to the width of the casing. The design is simple to operate, and the portable headphone amplifier casing is high in comprehensive practicality and easy to popularize and use.

The invention discloses an audio playing device and method as well as a mobile terminal. The audio playing device comprises an audio processing chip, an audio amplifier, a loudspeaker and a receiver, wherein a first port of the audio processing chip is connected with an input end of the audio amplifier and the receiver respectively and connected to a speech current amplifier inside the audio processing chip; an output end of the audio amplifier is connected with the loudspeaker. When audio information is transmitted to the audio processing chip, the speech current amplifier inside the audio processing chip transmits the audio information to the audio amplifier through the first port and then transmits the audio information to the loudspeaker for playing after amplifying the audio information, so that the problem that the user experience is affected due to the fact that the volume of earphones increases suddenly is solved. According to the device, all that is required is to connect the audio amplifier and the loudspeaker to a circuit between the first port and the receiver instead of additionally configuring an analog switch and an earphone amplifier, so that the cost is saved.

Provided herein are a headphone amplifier circuit for a headphone driver, an operation method thereof, and a universal serial bus (USB) interfaced headphone device using the same. The output stage of the headphone amplifier circuit is improved to have a differential output structure so as to effectively solve the crosstalk issue and increase the isolation between the left and the right channels such that the audio content presents a spatial perception and a distance perception more specifically.

A portable earphone amplifier provided by the present invention includes a charging module, a positive and negative boost module, a filament power supply module, a 35V boost circuit module and an amplifying circuit module, wherein the charging module is respectively powered by the positive and negative boost modules and the filament The module is connected with the 35V boost circuit module, which is used to provide power to the positive and negative boost modules and the filament power supply module; The operation provides voltage; the filament power supply module is connected to the filament of the electronic tube; the amplifying circuit module adopts the dual amplifier circuit of the electronic tube pre-stage buffer tuning circuit and the post-stage integrated op-amp amplifier circuit for secondary coupling; among them, the electronic tube pre-stage buffer tuning circuit The audio circuit is an electronic tube signal amplifying circuit; the post-stage integrated operational amplifier amplifying circuit is an amp signal amplifying circuit; this structure greatly reduces the size and required volume of the power supply circuit.

The invention relates to one audio earphone amplifier in electron sound technique field, which comprises front appendix buffer circuit, core power drive circuit, source direct current servo circuit, wherein, the audio input signals pass through level part, first integration computation amplifier, resistance RR2, first integration amplifier LM4766, resistance RoR1 and earphone socket; the resistance RR5 are over resistance RoR1 and LM4766 reverse phase end; LM4766 reverse phase input end is connected to earth resistance RR3; the resistance RR7 are over connection point and second integration amplifier NE5532 input end.