An amplifier performs analog amplification on a signal I_A with a gain corresponding to a state GS and outputs the amplified signal as a signal M_A. An ADC converts the signal M_A to a digital signal and outputs the digital signal as a signal M_D. Analog comparators and a down-determination unit detect that the signal M_A exceeds a first level, and cause the state GS to transition to a state of gain of the next lower stage. Digital comparators and an up-determination unit detect that the signal M_D has been continuously lower than a second level for a predetermined period, and cause the state GS to transition to a state of gain of the next higher stage. The restoration circuit performs digital amplification on the signal M_D with a gain corresponding to the gain of the amplifier and outputs the amplified signal as a signal O_D.

Disclosed are a load resistor control based signal amplification apparatus and an audio terminal including the same. The signal amplification apparatus according to the exemplary embodiment of the present disclosure selects at least one load resistor based on a load value of an output terminal connected to an output end and controls a current by means of at least one selected load resistor to amplify the audio input signal and output the audio output signal.

Provided is a method for audio peak reduction using an all-pass filter, including: determining a delay parameter m and a gain parameter g based on a formula (1):

[00001]$\begin{array}{cc}\underset{m,g}{\arg \min }\underset{n}{\max }.Math.y_{m,g}\left(n\right).Math.,& \left(1\right)\end{array}$

absolute peak map

[00002]$Y\left(m,g\right)=\underset{n}{\max }.Math.y_{m,g}\left(n\right).Math.,$

y.sub.m,g(n) represents a processed signal with a time-domain response function and is calculated based on a formula (2): y.sub.m,g(n)=(h.sub.s*x)(n)(2), where h.sub.s represents an impulse response function, x (n) represents an input signal, and h.sub.s is calculated based on formula (3):

[00003]$\begin{array}{cc}{H}_S\left(z\right)=\frac{g+z^{-m}}{1+{\mathrm{gz}}^{-m}}.& \left(3\right)\end{array}$

This method is widely used in the reproduction, storage and broadcasting of sound, and the computational complexity is small, which i

A vacuum tube subwoofer extraction circuit system includes: a front-end circuit; and a vacuum tube subwoofer extraction circuit connected to the front-end circuit, the vacuum tube subwoofer extraction circuit including: a small signal amplification vacuum tube for receiving an input signal from the front-end circuit and outputting an audio signal; and a passive filtering circuit connected to the small signal amplification vacuum tube and adapted to perform a filtering process on the audio signal so as to output a filtered signal, wherein the front-end circuit includes a switch power circuit for providing low voltage to the vacuum tube subwoofer extraction circuit, wherein the small signal amplification vacuum tube does not have gain effect on the input signal.

A vacuum tube subwoofer extraction circuit system includes: a front-end circuit; and a vacuum tube subwoofer extraction circuit connected to the front-end circuit, the vacuum tube subwoofer extraction circuit including: a small signal amplification vacuum tube for receiving an input signal from the front-end circuit and outputting an audio signal; and a passive filtering circuit connected to the small signal amplification vacuum tube and adapted to perform a filtering process on the audio signal so as to output a filtered signal, wherein the front-end circuit includes a switch power circuit for providing low voltage to the vacuum tube subwoofer extraction circuit, wherein the small signal amplification vacuum tube does not have gain effect on the input signal.

A method for compensating for a change in back electric motive force in a transducer in a device, wherein the transducer is driven by an output signal output by an amplifier, and a back volume of the transducer is formed by an enclosure within the device. The method comprises: receiving an input signal; determining, based on a characteristic of the transducer that the transducer has moved from an equilibrium position within the device; and based on the determination, adjusting a gain applied to the input signal by the amplifier to generate the output signal.

Provided is a method for audio peak reduction using an all-pass filter, including: determining a delay parameter m and a gain parameter g based on a formula (1): $\begin{array}{cc}\underset{m,g}{\arg \min }\underset{n}{\max }.Math.y_{m,g}\left(n\right).Math.,& \left(1\right)\end{array}$
absolute peak map $Y\left(m,g\right)=\underset{n}{\max }.Math.y_{m,g}\left(n\right).Math.,$
y.sub.m,g(n) represents a processed signal with a time-domain response function and is calculated based on a formula (2): y.sub.m,g(n)=(h.sub.s*x)(n)(2), where h.sub.s represents an impulse response function, x (n) represents an input signal, and h.sub.s is calculated based on formula (3): $ H S ( z ) = AUDIO DISTORTION COMPENSATION 20200036356 · 2020-01-30 · Cirrus Logic International Semiconductor Ltd. · Hezi Zhu, Roberto NAPOLI, Jie Su, Waleed Eshmawy A method for compensating for a change in back electric motive force in a transducer in a device, wherein the transducer is driven by an output signal output by an amplifier, and a back volume of the transducer is formed by an enclosure within the device. The method comprises: receiving an input signal; determining, based on a characteristic of the transducer that the transducer has moved from an equilibrium position within the device; and based on the determination, adjusting a gain applied to the input signal by the amplifier to generate the output signal. A/D conversion device and A/D conversion method 11894858 · 2024-02-06 · Yamaha Corporation · Kenji ISHIZUKA An amplifier performs analog amplification on a signal I_A with a gain corresponding to a state GS and outputs the amplified signal as a signal M_A. An ADC converts the signal M_A to a digital signal and outputs the digital signal as a signal M_D. Analog comparators and a down-determination unit detect that the signal M_A exceeds a first level, and cause the state GS to transition to a state of gain of the next lower stage. Digital comparators and an up-determination unit detect that the signal M_D has been continuously lower than a second level for a predetermined period, and cause the state GS to transition to a state of gain of the next higher stage. The restoration circuit performs digital amplification on the signal M_D with a gain corresponding to the gain of the amplifier and outputs the amplified signal as a signal O_D. Integrated Switch and Self-Activating Adjustable Power Limiter 20190296722 · 2019-09-26 · Jianhua Lu, Naveen Yanduru, Edward Nicholas Comfoltey, Michael Conry, Chieh-Kai Yang A fast response time, self-activating, adjustable threshold limiter including a limiting element LE, a first coupling element CE.sub.1 electrically connected from a signal node of LE to a control input of LE, and a second coupling element CE.sub.2 electrically connected from the control input of LE to a nominal node of LE. An initial bias (control) voltage is also supplied to the control input of LE to dynamically control the limiting threshold for the limiter. Embodiments include usage of self-activating adjustable power limiters in combination with series switch components in a switch circuit in lieu of conventional shunt switches. $