a stereo system usually contains an amp and preamp. it is impossible to measure the contribution of each to the overall sound.
so, there is no definitive answer to the question.
it is obvious that the preamp 's signal is usually a fraction of an amp and feeds an amp, whose output exceeds several amps. one may conclude that the preamp is the more important component. but one cannot generalize. there are other factors, such as the speakers power requirement and its impedance as a function of frequency.
some electrostatics are hard to drive, so the amp, may be more critical in explaining the variation in the sound of a speaker than the preamp.
so, there is no definitive answer to the question.
it is obvious that the preamp 's signal is usually a fraction of an amp and feeds an amp, whose output exceeds several amps. one may conclude that the preamp is the more important component. but one cannot generalize. there are other factors, such as the speakers power requirement and its impedance as a function of frequency.
some electrostatics are hard to drive, so the amp, may be more critical in explaining the variation in the sound of a speaker than the preamp.