Mullard EL34 Blackburn Xf2 · matched quad
Blackburn-plant brown-base EL34s, Xf2 date code, four bottles, four matching foil boxes.
- SKU
- MS-VT-0417
- Era
- 1950-2000
- Condition
- NOS, tested and burned-in 48 hours; matched within 2mA on a Maxi-Matcher
- Dimensions
- 112 × 52 mm (H × Ø)
- Weight
- 58 g each
- Provenance
- Acquired 2021 from the estate of a retired BBC transmission engineer in Kent.
- Category
- Vacuum Tubes & Valves
- Tags
- mullardel34matched-quadblackburnnos
Blackburn-plant EL34s from 1966 bearing the Xf2 date code — the brown-base variant that Marshall, Hi-Watt, and Fender restorers pay real money for. The construction is unmistakable: coined getters, deep-etched base ink, and the internal mica shape unique to the plant's tooling in the mid-sixties.
All four still carry their Mullard-branded fibreboard sleeves, most with the little foil-lined liner intact. Getters are silvered and even, filaments strike within one second of each other, and cathode current variance across the quad is under two milliamps at 400V plate.
We do not expect to see another quad of these leave the shop this year. They are, in the flat terms of the trade, correct.
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