Same tube with 12.6V heater — requires different heater supply wiring
6N10S
Soviet equivalent (6Н10С) — same Octal base, similar characteristics, verify pin compatibility before substituting
6SL7GT
Similar high-mu twin triode successor but Noval/Octal pinout differs and sections have separate cathodes
Electrical Specifications
Absolute Maximum
Anode Voltage (max)Max Plate Voltage250V
Heater-to-Cathode Voltage (max)Max Heater-Cathode Voltage90V
Max Grid ResistorMax Grid Resistor0.5MΩ
Typical Operating
Anode Voltage (typical)Plate Voltage250V
Notes
Both triode sections share a common cathode (pin 6). This makes the 6SC7 particularly suited for phase-inverter service but limits flexibility compared to twin triodes with separate cathodes (e.g. 6SL7GT).
Pin 1 (shell) is internally connected to pin 6 (cathode) on the metal-envelope 6SC7. The 6SC7GT glass variant uses the same basing.
The Rg_max value of 0.5 MΩ applies when both sections are used as a phase inverter. For phase-inverter service, the cathode resistor should not be bypassed by a capacitor — omission of the bypass condenser assists in balancing output voltages.
Originally introduced by RCA in November 1938 as a single-ended metal type specifically designed for phase-inverter service.
Pin Layout — Octal
1Shell (internally connected to Cathode)
2Plate 2 (Triode section 2)
3Grid 2 (Triode section 2)
Socket-Compatible Tubes ⚠ Not electrically compatible