This will at least do two things: reduce the output impedance and linearize the CF.
相对上面的三极接法，下面的线路最少有两点不同：减低输出阻抗和提高阴随的线性度。
Here are some measurements of the two circuits. Blue curve is without and red curve with g2-feedback. The output impedance is 690 ohm for the plain CF and 280 ohm with g2-feedback.
下图蓝线是上面的第一图（三极接法），輸出阻抗为 690Ω。
下图红线是上面的第二图，帘栅引入反饋。輸出阻抗下降至 280Ω。
Most of the distortion belongs to the common cathode block, so it might be worthwhile to play with the working point for that stage.
大部分的失真皆由增益级产生，故应多从工作点处着手，如计算和调整 . . . 可能会有惊喜!
发表于 2011-11-22 22:16
