Voltage Drop (typical)Tube Voltage Drop (at 125 mA)50V
Notes
Brans Vademecum lists 6AX5GT as equivalent to 6X5. Both share the same Octal pinout (base 6S), 6.3V/1.2A heater, and similar electrical ratings. The 6AX5GT has slightly different heater warm-up characteristics.
The 6AX5GT is already listed as an equivalent of the 6X5 in this repository.
Maximum ratings vary by filter type: with capacitor-input filter, max AC plate voltage is 350V RMS per plate at 10 uF; with choke-input filter, max is 450V RMS per plate.
Effective plate supply impedance limits: 50 ohm per plate minimum for capacitor-input up to 10 uF, 105 ohm per plate minimum for larger capacitors.
Maximum hot-switching transient plate current is 2.6 A (for 0.2 second max duration) — relevant for capacitor-input filter circuits.
The voltage drop is relatively high (~50V at 125mA total) compared to directly-heated rectifiers like the 5Y3 (~60V at 125mA). This is typical of indirectly-heated full-wave rectifiers.
MIL-HDBK-213A classifies this as a full-wave rectifier. No military substitute is listed.
Pin Layout — Octal
1No Connection
2Heater
3Anode 1 (Plate 1)
4
Socket-Compatible Tubes ⚠ Not electrically compatible