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只要配对好应该不会失败，差不多的电路
The preamplifier that appears in the figure is a completely symmetrical preamplifier, from the input as the exit and it works in Class A. It does not have somebody innovation, simply it uses good solutions, in order the result is what should. Such proposal is the use transistors matched [Q1, 2], that finds in the same chip with result the thermic and other characteristics are ''perfect''. It can they are replaced by simple transistors as the BC550C and BC560C it's enough you enter in the fatigue to matched you pairs with similar characteristics. With the TR1 we can if it needs we regulate the Offset voltage in the exit of unit. It can however be suppressed and it's replaced with two resistances 82 ohm in the place of R6 -7. A point that it should I accent it's that diodes D1 and D2 it should they are placed very near in transistors Q3 and Q4 respectively, so that they have common thermic behavior. The himself should become also with transistors Q8 - Q10 and Q9 - Q11 respectively. The regulation of out current becomes with the TR2, in 20mA that corresponds in 200mV fall across resistance R25. If we want the response of unit in the low frequencies she becomes ''flat'' it should jumper the capacitor C12 or him we abolish. The currents that run through the circuit in various points appear in the figure. In table 1 exist various voltages in utmost materials that they will help in the regulation.
Google翻译：
图中出现的前置放大器是一个完全对称的前置放大器，从输入端作为出口，工作在A类中。它没有人创新，只是使用了好的解决方案，以便得到应有的结果。这样的建议是使用匹配[Q1，2]的晶体管，在同一芯片中发现其热学和其他特性是“完美的”。可以将它们替换为简单的晶体管，因为BC550C和BC560C足以使您输入疲劳值以匹配具有相似特性的线对。使用TR1，我们可以根据需要调节单元出口的失调电压。但是，可以将其抑制，并用两个电阻82 ohm代替R6 -7。我要强调的一点是，二极管D1和D2应该分别放置在晶体管Q3和Q4中非常靠近的位置，以便它们具有共同的热行为。他本人也应该分别使用晶体管Q8-Q10和Q9-Q11。输出电流的调节随TR2的变化而变化，在20mA相当于电阻R25上200mV的下降。如果我们希望单元在低频下的响应变得“平坦”，则应将电容器C12或他跨接起来，我们将其取消。图中出现了流经电路各个点的电流。在表1中，最大程度的材料中存在各种电压，它们将有助于调节。 |
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发表于 2020-6-7 16:49
楼主
