Preamplifiers and Power Amplifiers

Part 1

• Is the preamplifier a separate component of an entertainment system?
• Why is the amplifier is the control center of a system?
• What functions does the preamplifier perform?
• What input signal levels do power amplifiers require?
• What electronic components are found in a passive level control preamp?
• What is a phono amplifier?
• What is the typical voltage of a line stage preamplifier input signal?
• What is the function of the record output selector?
• What additional functions do A/V preamplifiers perform?
• Why are Digital preamplifiers bound to become more popular?
• What is the role of the amplifier?
• What is the ideal behavior of an amplifier?
• What components of the amplifier influence the quality of its sound?
• What is the most expensive stage of an amplifier?
• Why are capacitors used in amplifiers? Can you describe their function?
• Why is «clipping» dangerous to speakers?
• What determines the capability of an amplifier to handle low speaker impedance?
• When is a speaker a difficult load, for the amplifier?
• Ideally how should an amplifier behave, when the speaker impedance is halved?
• How do we define class A amplifiers?

Part 2

• What is class B operation?
• Why class A/B amplifiers are popular?
• Why vacuum tube amplifiers are favored by audiophiles?
• What are the main advantages and disadvantages of each type of tubes used in amplifiers?
• What are the two types of digital power amplifiers?
• What form is the digital input signal converted to by a true digital power amplifier?
• How is the PWM data converted to analog audio signal?
• Why is the multichannel A/V integrated amplifier, a common choice for setting up a Home Theater system?
• Why are some typical audio adjustments that can be performed by an A/V amplifier?
• Why is a typical A/V amplifier capable of being the control center of a Home Theater system?
• What are the technical characteristics of an amplifier capable of driving low impedance speakers?
• How many speakers can my amplifier drive?
• How much power do I need?
• My amplifier does not have a subwoofer output. How can I connect my subwoofer?
• My amplifier delivers 100 W per channel. Do I need to buy speakers with the same power rating?
• What is amplifier bridging?