2171671

Information

• Patent Grant
• 2171671

• References
• Source

• Patent Number

  2,171,671

• Date Filed

  Not available

• Date Issued

  Tuesday, September 5, 1939
  85 years ago

• CPC

  • H03G9/10 - for tone control and volume expansion or compression

• US Classifications

  • 333 - Wave transmission lines and networks
  • 217 - Wooden receptacles
  • 330 - Amplifiers
  • 381 - Electrical audio signal processing systems and devices