On power amps, the doubling of power results in a 3db increase. An increase from a 50 watt to a 100 watt power amp would result in a 3db increase in sound pressure levels. So increasing an amp from 50 watts to 200 watts would increase the SPL by 6db. As this is a logarithmic progression, you can see that SPL levels reach a ceiling rather quickly! For voltage amps (phono amps & preamps) the doubling of VOLTAGE results in a 6db increase. Although this is not the specific answer to your question, it helps to understand what increasing power will mean in real world applications. Don't forget that you can increase power by reducing speaker impedance for SS amps (although this may result in a decrease in performance of certain parameters (bass damping and exceesive circuit heat) in certain amps. Many tube amps though, perform better when matched with a HIGHER impedance speaker, especially OTL (transformerless) amps. Here are the decibel formulae:
Watts...dbw = 30 x log (E2/E1)
Volts...dbv = 20 x log (E2/E1)
These formulae are useful for comparing the actual increase/decrease of power or voltage when working with amps that are not doubled (or halved) with respect to output.
Watts...dbw = 30 x log (E2/E1)
Volts...dbv = 20 x log (E2/E1)
These formulae are useful for comparing the actual increase/decrease of power or voltage when working with amps that are not doubled (or halved) with respect to output.