• Country
• United States of America (USA)

• Manufacturer / Brand
• Operadio Corp.; St. Charles (IL)

• Year
• 1948 ?

• Category
• Audio Amplifier or -mixer

• Radiomuseum.org ID
• 235691

• • alternative name: Operadio Mfg,

Click on the schematic thumbnail to request the schematic as a free document.

• Number of Tubes
• 6

• Valves / Tubes
• 6J7 6J7 6J7 6J7 6SN7GT 6X5GT

• Main principle
• Audio-Amplification

• Wave bands
• - without

• Power type and voltage
• Alternating Current supply (AC) / 110-120 Volt

• Loudspeaker
• - For headphones or amp.

• Material
• Metal case

• from Radiomuseum.org
• Model: Audio Pre-Amplifier 1A65 - Operadio Corp.; St. Charles IL

• Shape
• Tablemodel, with any shape - general.

• Notes

• AC Operated 4 Channel Audio Pre-Amplifier.

  Output mode A : 125 ohms single ended

  Output mode B : 1250 ohms single ended

  Output mode C: 500 ohms balanced line

  Output mode D : 5000 ohms balanced line

   

   

   

• Mentioned in
• Photofact Folder, Howard W. SAMS (4822-14 Set 52 Folder 14)

• Literature/Schematics (2)
• Rider Public Address Equipment Manual, Vol. 1

• Author
• Model page created by Friedrich Weber † 12.09.2014. See "Data change" for further contributors.

• Other Models

• Here you find 66 models, 43 with images and 32 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
  All listed radios etc. from Operadio Corp.; St. Charles (IL)