Carrlsbad2
That is a good Approximation, BUT
An Amp can ONLY produce a relative output within and given operating range. If you have say low power you can not get something from nothing, that isn't there to begin with and you will have a comparatively weaker output. If your Bias voltage is off or your output supply voltage is Low/High, your output will change along similar lines. The circuit can TRY to compensate but there is no circuit that can demand an output. Even a constant current amp has it's limitations.
On the other hand your statement about PP is right on and that is a great place to lock in some stability and consistency.