在一个电子管的壳内装有两个以上电极系统，每个电极系统各自独立通过电子流，实现各自的功能，这种电子管称为复合管。复合管是指用两只或多只三极管按一定规律进行组合，等效成一只三极管，复合管又称达林顿管。具体接法如下，以两个相同极性的三极管为例，前面为三极管集电极跟后面三极管集电极相接，前面为三极管射极跟后面三极管基极相接，前面三极管功率一般比后面三极管小，前面三极管基极为达林顿管基极，后面三极管射极为达林顿管射极，用法跟三极管一样，放大倍数是两个三极管放大倍数的乘积。
There are more than two electrode systems in the shell of an electron tube. Each electrode system achieves its own functions through the electronic current independently. This kind of electron tube is called composite tube. Composite tube refers to the combination of two or more transistors according to certain rules, which is equivalent to a triode. Composite tube is also called Darlington tube. The specific connection method is as follows: Take two triodes with the same polarity as an example, the front triode collector is connected with the rear triode collector, the front triode emitter is connected with the rear triode base, the power of the front triode is generally smaller than that of the rear triode, the front triode base is extremely Darlington base, and the rear triode is fired. Extremely Darlington emitter is used in the same way as transistor. Amplification multiplier is the product of two transistor amplification multipliers.