1. The problem statement, all variables and given/known data I am trying to analyze the following circuit: "Note that if the two 2N5485s approximately match in their characteristics, not only is the voltage gain unity, but the DC offset is small: the constant current due to Q2 creates a constant voltage drop across R1. Furthermore, since the gate of Q2 is at the same voltage as the bottom of R2, this should also be true for Q1 and R1. This the output voltage must follow the source voltage of Q1." I am trying to understand the overall operation of the circuit, with a focus being on how to figure out that the last sentence is true. 2. Relevant equations 3. The attempt at a solution I know that the current source provided by the addition of a second FET creates a constant current and has a very high Zout relative to Zin. This causes the constant voltage drop across R1, as mentioned above. I am really struggling to understand the last statement of the paragraph and how that relates to the impedance. Thanks in advance for any hints you can provide.