The Electrical Era (1920s-1940s)

  • Vacuum Tube Technology: Triodes, pentodes, tube characteristics
  • Early Microphone Development: Carbon, condenser, ribbon, dynamic
  • Comprehensive Microphone Technology: Transducer principles, polar patterns, frequency responses
  • Electrical Amplification: Gain stages, impedance matching
  • Transformer Technology: Audio transformers and their properties
  • Early Broadcasting: AM radio, transmission techniques
  • Broadcast Standards: Early technical specifications and practices
  • Disc Cutting: Electrical disc mastering, cutting lathes
  • Passive Components: Resistors, capacitors, inductors, and their effects
  • Basic Circuit Theory: Series/parallel circuits, frequency response
  • Early Electrical Filters: LC filters, tone controls
  • Early Recording Chain: Microphone to amplifier to cutter head
  • Power Supplies: Rectification, filtering, regulation for audio equipment
  • Noise & Interference: Electrical noise sources and mitigation
  • Telephone Technology: Audio transmission over wires, bandwidth limitations