Tube-number record
XCC 189 / 4ES8
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BrandIBRAPE / MINIWATT
ClassDouble Triode
BaseNoval (B9A)
Filament4.5 V @ 600 mA
Construction
Primary TypeDual triode
EnvelopeGlass
Sections2
Filament / Heater
Warm-up Time11s
Heater NotesIndirect heating, series supply
Absolute Maximum Ratings
Plate Voltage130 V
Plate Dissipation1.8 W
Grid 1 Voltage-50 V
Cathode Current22 mA
H-C Voltage50 V
Audio Performance
Key Features
- Variable transconductance
- Indirectly heated
- Designed for Cascode amplifier circuits
- Low noise
Typical Operation
| Mode | Plate V | Gm (µmhos) | Rp (Ω) | µ | Plate mA |
|---|---|---|---|---|---|
| Single Section | 90 V | 12500 | — | 34 | 15 mA |
Application Notes
The a-g-k system should be used as the input section with the cathode grounded, and the a'-g'-k' system as the grid-grounded stage. When used in cascode amplifiers, a voltage divider is required for the grid of the grounded-grid section to avoid exceeding the maximum plate voltage.
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