High-fidelity transistor audio power amplifier

Abstract

The invention discloses a high-fidelity transistor audio power amplifier which mainly comprises a prime amplifier and a post amplifier. An input port of the prime amplifier is connected with an audio input signal input by an external audio input device, the output port of the post amplifier is connected with an external audio output device, and the output port of the prime amplifier is connected with the input port of the post amplifier through a resistor. The post amplifier mainly comprises a common-emitter common-base differential input stage circuit, a common-emitter common-base principal voltage amplification stage circuit, a UBE multiplying and temperature protection circuit, an improved three-level Darlington push-pull output stage circuit, an alternative circuit / direct current negative feedback circuit, an active servo circuit, a voltage-stabling and filter circuit, a constant flow source circuit, an image constant flow source, two RC resistor-capacitor filter circuits, four capacitor filter circuits, a horn protection circuit and a post power circuit, wherein the power circuit supplies electricity to the common-emitter common-base differential input stage circuit, the common-emitter common-base principal voltage amplification stage circuit, the UBE multiplying and temperature protection circuit, the improved three-level Darlington push-pull output stage circuit, the alternative circuit / direct current negative feedback circuit, the active servo circuit, the voltage-stabling and filter circuit, the constant flow source circuit, the image constant flow source, the two RC resistor-capacitor filter circuits, the four capacitor filter circuits and the horn protection circuit. The high-fidelity transistor audio power amplifier achieves the conditions that a circuit is direct-current and wide-band, and can effectively improve listening feelings.

Description

technical field

[0001] The invention relates to the field of audio power amplifiers, in particular to a high-fidelity transistor audio power amplifier. Background technique

[0002] At present, household transistor high-fidelity audio power amplifiers, household electronic tube high-fidelity audio power amplifiers, professional audio power amplifiers, and car audio audio power amplifiers are all developing rapidly. Existing transistor audio power amplifiers usually consist of pre-amplifiers and post-amplifiers. I have seen many circuits at home and abroad, including audio power amplifiers in the United States, Britain, Germany and other countries. To make the circuit work stably, coupling capacitors are added to the signal input and output terminals of the pre-amplifier and the signal input of the post-amplifier. However, the added coupling capacitors will have a certain adverse effect on the frequency response and sound quality of the amplifier. Moreover, the circuit they ...

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