摘  要

隨著國家經(jīng)濟(jì)蒸蒸日上，現(xiàn)代科技不斷發(fā)展，這些使人們在物質(zhì)享受之余，也有了更多的精神享受的需要。其中之一：音樂，便是一種古老的享受形式。而高保真音響就是欣賞音樂的物質(zhì)基礎(chǔ)。

本論文將以性價(jià)比為導(dǎo)向，兼顧基本的高保真的技術(shù)指標(biāo)，討論了適合初級(jí)發(fā)燒友的高保真功放。論文由淺至深，結(jié)合圖示給出了高保真音響的相關(guān)知識(shí)，以及整個(gè)功放的工作過程的細(xì)節(jié)。同時(shí)還介紹了各個(gè)主要芯片自身的特點(diǎn)及如何去設(shè)計(jì)這個(gè)系統(tǒng)來滿足一定的技術(shù)指標(biāo)。論文盡可能通俗地來介紹高保真音響，讓大家能從中學(xué)到基本的高保真音響的知識(shí)的同時(shí)，還能學(xué)會(huì)如何制作高保真音頻放大器。

在技術(shù)層面上，系統(tǒng)主要是采用集成芯片來完成的，因此對于一個(gè)初級(jí)發(fā)燒友來說相對簡單，這個(gè)設(shè)計(jì)中用到了NE5532(曾經(jīng)的“運(yùn)放之皇”)做前置放大芯片，典型的增益為20dB；用NSC公司的LM1036做音調(diào)芯片，通過改變直流控制電壓來實(shí)現(xiàn)音調(diào)控制。后級(jí)功率放大部分用的也是NSC公司的一款經(jīng)典芯片――LM1875芯片，用4片LM1875駁接成了左右聲道的BTL電路,以取得更大的功率以及更好的音效。

在論文的后面部分，著重的講述了制作和調(diào)試中遇到的軟件、硬件上的問題以及如何解決，并給出了高保真音頻放大器性能指標(biāo)的國家標(biāo)準(zhǔn)測量方法。這些可以成為大家制作過程中的一些的提示以及測試的依據(jù)。

關(guān)鍵詞：高保真；集成芯片；BTL；音調(diào)控制

Abstract

With the development of our country’s economy and the modern technology. People no –longer just enjoy the happy brought from material, they also learned to enjoy the spiritual things. For instance: Music, an old fashion of the enjoyments. And Hi-Fi(high fidelity) audio system is the very suitable intermedia for enjoying music.

So this dissertation focused on the Hi-Fi amplifiers for those primary audiophiles on this field. It tried to let people cost less and at the same moment , get enough enjoyment from Hi-Fi amplifiers and satisfy those basic standards of Hi-Fi system. This dissertation presented the ideas from easy to hard, and described the relative knowledge of the Hi-Fi audio system with those graphics and diagrams. It also wrote about the details of the whole working process of this design gradually. This dissertation also introduced those characteristics of those chips used in my design, and how to realize those system’s targets given .The dissertation tried to introduce Hi-Fi audio system commonly,and let  you learn some basic knowledge of this Hi-Fi system, at the same time , eventually learn how to accomplish a Hi-Fi audio amplifier.

Refer to the technology, IC was used to finish this graduate design, because it's relatively easier for primary audiophiles to design a audio amplifier. The pre-amp is NE5532, which was ever called as "The KING of amplifiers" ,and its typical gain is 20dB;LM1036 produced by NSC(National Semiconductor Company) was used here for tone adjustment IC. And LM1036’s tone control can be controlled by changing the DC control voltage. The second amplifier IC is LM1875, also made by NSC. It is very classical . Four LM1875 chips were used to make a BTL(Balanced  Transformer  Less) circuit of  each channel to achieve more power and  to make the whole system’s timbre to be better.

The last paragraph of this dissertation, I mainly introduce some software and hardware problems I met during making the board and debugging, and how I solved those problems. Also I presented you the national standard test methods for audio amplifier characteristics. Hope these can be your hints and help during your executing for audio amplifier.

Key words: Hi-Fi; Integrated Circuit; BTL; Tone control

目    錄

引言 1

1  高保真音響系統(tǒng) 1

1.1 高保真音響系統(tǒng)定義 1

1.2 高保真音響系統(tǒng)組成 2

2  高保真功率放大器 3

2.1 功率放大器種類 3

2.2 高保真功率放大器主要技術(shù)指標(biāo) 4

3  功放電源 8

3.1 功放電源概述 8

3.2 功放電源組成 8

3.3 整流濾波電路 10

3.4 穩(wěn)壓電路 13

4  方案論證及闡述 14

4.1 設(shè)計(jì)要求 14

4.2 方案論證 14

4.2.1后級(jí)放大器方案選定 14

4.2.2前置放大器方案選定 14

4.2.3音調(diào)芯片方案選定 15

4.2.4電源方案選定 15

4.3 具體方案闡述 15

4.3.1前級(jí)放大器方案闡述 15

4.3.2后級(jí)放大器方案闡述 19

4.3.3功放電源方案闡述 22

5  高保真功放制板 23

5.1 制板注意事項(xiàng) 23

5.2 制板經(jīng)驗(yàn)總結(jié) 24

5.2.1制板步驟 24

5.2.2Protel99se的使用經(jīng)驗(yàn)總結(jié) 25

5.2.3制板遇到的問題 26

6  功放調(diào)試 26

6.1 調(diào)試步驟 27

6.2 模塊調(diào)試 27

6.2.1電源調(diào)試 27

6.2.2音調(diào)模塊調(diào)試 27

6.2.3前置放大模塊調(diào)試 28

6.2.4后級(jí)功放模塊調(diào)試 28

6.3 整體調(diào)試 28

7  高保真功放性能指標(biāo)測試 29

7.1 性能指標(biāo)測試的必要性 29

7.2 主要性能指標(biāo)測試 29

7.3 測試所用儀器 32

7.4 測試結(jié)論 32

8  總結(jié) 33

8.1 完成程度 33

8.2 技術(shù)優(yōu)點(diǎn) 33

8.3 技術(shù)缺陷 33

8.4 畢設(shè)感受 33

謝  辭 34

參考文獻(xiàn) 35

附  錄 36

附錄1電路原理圖 36

附錄2 PCB 圖 39