TubeDatabase
  • Tubes
  • Testers
  • Companies
  • Submit
  • About

Tube Database (7,341 tube types · 1,270 archive entries)

Other (3,257 tube types), Pre (2,314 tube types), Power (1,030 tube types), Rectifier (740 tube types)
DisclaimerSubmit a tube

Tube-number record

4074-A

0 archive entries

BrandStandard
ClassDouble Triode
Base7-pin (non-miniature)
Filament6.3 V @ 800 mA

Construction

Primary TypeDual triode
EnvelopeGlass
Sections2

Filament / Heater

Heater NotesConstant voltage type

Absolute Maximum Ratings

Plate Voltage300 V
Plate Dissipation5 W
Cathode Current50 mA

Audio Performance

Power Output12 W
Key Features
  • Indirectly heated oxide coated cathode
  • Anode connected to top cap type B

Typical Operation

ModePlate VGm (µmhos)Rp (Ω)µPlate mA
Single Section Constants250 V3000470014—
Class A AF Amp (2 sections parallel)300 V———30 mA
Class B AF Amp (Push Pull, 300V condition)300 V—7000—

Application Notes

Two sections are identical. For Class A, two sections connected in parallel at the socket. For Class B, two sections connected in push-pull. The fixed bias for Class C should be at least 15 volts to protect the valve in case of failure to oscillate.

Filters

0 tubes found

Manufacturers

Brands

    0 results
    37 mA
    Class C Push Pull Amp300 V———80 mA