Semiconductor Devices: Class A with Reactive Load

The typical analysis of a class A power amplifier utilizes a load that is purely resistive. A real world load, such as a loudspeaker, is reactive, and can have a phase angle that varies with frequency. How does this affect the load line? We'll find out.
Note: There is an error in the schematic. Vload should be immediately to the right of the output coupling capacitor, not at the far right. Fortunately, we are not using that node in this analysis, so it is of no practical concern to our discussion.
References: Semiconductor Devices: Theory and Application/2E; Chapter 8, sections 3 and 4.
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[@rayc1557]

Related to this... The Bode graphs of headphone amplifiers look very different when the load is a real headphone vs a fixed resistor.

[@ElectronicswithProfessorFiore]

That is a potential issue (no pun intended) and another reason why real-world vs. idealized loads should be used in design and test. Generally speaking, if the amplifier has an appropriately low output impedance, there should not be much change given typical headphones (assuming direct drive, and not a high power amplifier fitted with an L pad to reduce the signal).

[@kennarnett8220]

Excellent!