New book: Current-Driving of Loudspeakers

[E-Stat]

He is refering to the power (in this case voltage) input from the wall, not the voltage from an audio source.

Which completely ignores what amplifiers do to the signals sent to them. They add gain to what the sources generate. Such is a specification provided by most amplifiers. Most power amps specify their gain as a value from between 24 and 30 db. Phono level preamps like my SP-9 MKIII provide 67 db of voltage gain to the signal. Power supply voltage found at the wall is irrelevant to what the amplifier gain stages do to sources in the real world. I think he should demand a refund for the superficial understanding of electrical theory he got with his three years of *training*.
rw