The output impedance of a circuit cannot be printed or plotted directly.
The output impedance of the pair is now halved.
A real-world current source has a very high, but finite output impedance.
Hence, the output impedance of the amplifier limits the maximum power that can be provided.
Here, Z is the output impedance of the amplifer.
The output impedance cannot be controlled other than through feedback.
One can however measure its input or output impedance.
Without feedback, this arrangement results in an output impedance of 6-8 ohms.
Finally, the 2R resistance is in series with the digital output impedance.
Because R is often large, the output impedance of this circuit can be prohibitively high.