← Browse Mullard High quality — base, heater, all universal parameters present, and ≥50% of desirable parameters filled in. Safe to use for design decisions.
Known Equivalents & Substitutes
VR56 CV1056 BVA247 10E/11402 VT201
Similar Tubes (Not Drop-In Compatible)
American equivalent with similar characteristics but verify pin compatibility Low-microphonic version of EF36 with tighter manufacturing tolerances Improved low-microphonic variant of EF36/EF37 lineage Electrical Specifications
Absolute Maximum
Anode Voltage (max) Anode Voltage (max) 300V
Screen Voltage (max) Screen Voltage (max) 300V
Anode Dissipation (max) Anode Dissipation (max) 2.5W
Typical Operating
Anode Voltage (typical) Anode Voltage (typical) 250V
Notes
Military designation VR56 (UK). Extensively used in wartime radar and communications equipment. The EF37 and EF37A are improved low-microphonic versions of this type. Octal base with top grid cap connection (pin arrangement IO/K8A). Pin Layout — Octal
1 2 3 4 5 6 7 8
1 No Connection
2 Heater
3 Anode (Plate)
4
Socket-Compatible Tubes ⚠ Not electrically compatible