# Class a amplifier load capacitance

What would happen in a class a amplifier if I connect a capacitor in series with the load resistor (between power supply and the transistor collector)? My goal was to block the dc qiescent current to reduce energy wasted as heat.

I apologize in advance for my english (i'm italian) an for my probably stupid question.

• The transistor needs a DC voltage across it in order to work, so your amplifier likely wouldn't work Dec 3 '18 at 18:47

The charging of the capacitor and subsequent drop in collector voltage is visible on $$\V(cap)\$$, and the waveform for $\V(out)\$ is quite distorted due to the capacitor.
However, if I replace the capacitor with a short circuit, a mostly distortion free sine wave is visible on $$\V(out)\$$, with an amplitude of about 2V pk/pk.
Finally, for small signal amplifiers using BJTs, the transconductance $$\g_m\$$ (and input resistance $$\r_e\$$) is dependent on how much quiescent current is flowing through the transistor.