Sorry for such elementary question.
As anyone knows emitter follower design of BJT has some specifications . For example they are suitable for driving low impedance loads and so. But because the gain is less or maximum equal to 1, if one needs some degree of amplification, it should be done before ( at least it is what I think being rational) .
On the other hand BJTs are best suited for small signals. Please let me explain a little more by an example ( I am asked to be more specific in my questions! ).
Let's assume we have a 200 mV pk-pk signal and want to drive a 50 ohms load with 10 volt pk-pk. What I think is to amplify the signal to a 10v pk-pk first ( with Op-Amp/FET/ BJT or anything, it is not the matter here). Then I feed it to an emitter follower for impedance matching and obtaining enough current.
If we have a VCC=20v, now the input signal of the BJT in emitter follower design(10v) is not assumed as a small signal. This is a very common design and I can not understand how to manage it.