How can I set the quiescent current for a grounded-emitter amplifier?
Indeed this simple CE circuit on its own isn't easy to control. When you would tweak the biasing voltage (as jonk suggests in his comment) then you need to do that again for each transistor as all transistors are slightly different. Also transistor behavior changes over temperature so even if you tweak it to 1mA at 25 degrees C, at 40 C the current will be different.

The amplification of Vbe to Ic means that a small change in Vbe results in a large change in Ic (that's the actually the amplification we want to use). We want that large amplification for our signal (AC) but for the biasing (which is DC) it is a pain. So can we lower the gain for DC? Sure, like this:







simulate this circuit &ndash; Schematic created using CircuitLab

In this circuit I lowered the DC gain to about 10 while the AC gain is largely unchanged. This does mean that the DC voltage at the emitter is increased somewhat though, that can limit the output voltage swing. But biasing control and predictability is much better.

Another solution is to use a DC feedback loop, the DC voltage at the collector depends on Ic so if we compare that voltage to a reference voltage we get an error signal we can use to control the biasing of the base of the NPN.