Same 9HF pinout and dissimilar double triode structure, but different electrical characteristics (Unit 2: gm=7.5 vs 6.5 mA/V, Pa_max=10W vs 7W, Ih=0.925A vs 0.9A). Sams Tube Substitution Handbook lists as substitute.
6FR7
Same 9HF pinout and dissimilar double triode structure, but different electrical characteristics. Sams Tube Substitution Handbook lists as substitute for 6DR7.
Brans cross-lists — similar dissimilar twin triode but different characteristics; verify before substituting
Electrical Specifications
Section 1 — High-Mu Triode
Absolute Maximum
Anode Voltage (max)Max DC Plate Voltage330V
Anode Dissipation (max)Max Plate Dissipation1W
Cathode Current (max)Max Average Cathode Current20mA
Heater-to-Cathode Voltage (max)Max Heater-Cathode Voltage200V
Notes
Section #2 is identical to section #2 of the 6DE7 (Tung-Sol datasheet).
10DR7 is identical to the 6DR7 except for heater ratings and heater warm-up time (Tung-Sol datasheet).
Pin 2 and Pin 3 are both connected to the control grid of Unit No.2 (dual grid pins).
Heater positive with respect to cathode must not exceed 100V DC component.
Originally designed for vertical deflection circuits in television sets, but adopted by DIY audio designers as a driver/output tube in low-power amplifiers due to its combined high-mu voltage amplifier and medium-mu power section.
Pin Layout — Noval
1Plate (Unit No.2)
2Grid (Unit No.2)
3Grid (Unit No.2)
Socket-Compatible Tubes ⚠ Not electrically compatible