Mullard ECC33 rX1- Base
- Brown
- Bottle Height
- Short
- Code On Tube
- fX1 B7K
- Factory Code
- B - Mullard, Blackburn, B - Mullard, Blackburn
- Glass Color
- Clear Glass
- Mica
- Double
- Permanentid
- ef9s9wwr
- Pin Color
- Silver Pins
- Plate Color
- Matte Gray
- Tip Shape
- Round Tip
- Year
- 1957
