Amplifying Audio

Amplifying Audio

1. Block Diagram

   • Signal Source
     • Outputs audio signal
       • AC signal
       • Frequency between 20Hz and 20kHz
       • Amplitude usually a few millivolts
   • Pre-Amplifier
     • Boosts the amplitude
       • Boosts to levels well above noise level other blocks may add to
   • Tone Control
     • Adjusts the frequency balance of the signal
       • Boosts some ranges and cuts others
       • Compensates for imperfect transfer characteristics of the microphone, loudspeaker and human ear
   • Volume Control
     • Varible component that passes a fraction of the current
       • Fraction can be between all the signal of nothing at all
       • Passes the signal from the tone control to the voltage amplifier
   • Voltage Amplifier
   • Power Amplifier
   • Loudspeaker