功放电路中的前级放大,跟后级放大分别什么作用?

2024-11-11 15:34:17
推荐回答(3个)
回答(1):

前级放大器负责将信号整理与调整, 后级放大器把前级来的信号作大量放大来推动扬声器。
前级放大器又称为前置放大器,前置放大器是指置于信源与放大器级之间的电路或电子设备,是专为接受来自信源的微弱电压信号而设计的。对于微弱信号检测仪器或设备,前置放大器是引入噪声的主要部件之一。整个检测系统的噪声系数主要取决于前置放大器的噪声系数。仪器可检测的最小信号也主要取决于前置放大器的噪声。前置放大器一般都是直接与检测信号的传感器相连接,只有在放大器的最佳源电阻等于信号源输出电阻的情况下,才能使电路的噪声系数最小。

回答(2):

德利亚dl300纯功放最好~型号 DL-300 8欧负载 300W 4欧负载 500W 2欧负载 600W 桥接输出(8欧) 750W 输入 平衡桥式差分放大 输入阻抗 20K欧(平衡输入) 10K欧(不平衡输入) 最大输入电平 +20dB(7.75V;Ref0.775Vms) 输入灵敏度 8欧负载最大输出1.1V 电压增益 可调,最大32dB(40倍) 频率响应 20Hz~20KHz±0.5dB 上升时间 <7us 返转速度 50V/us(8欧负载) 输出阻抗 4欧~8欧 通道隔离度 110dB(1KHz),80dB(20KHz) 阻尼系数 20KHz~1KHz范围>500;20KHz时>70(8欧负载) 交流输入电压 220V.50~60Hz 信噪比 >110dB 总谐波失真 <0.05%

回答(3):

前级是音量放大后级是功率放大 如果是换功放里的找没后级的 如果是音箱就找带前级 3886的功放板6并好像有300w

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