Same Octal 6S pinout but much higher current rating (100 mA vs 40 mA) — pin-compatible upgrade path
6X5-GT
Same Octal 6S pinout and heater voltage but higher current rating (70 mA vs 40 mA) and higher Vdrop (22 V vs 16.5 V) — 6X5 can replace 6ZY5-G but not the reverse in high-current circuits
Electrical Specifications
Absolute Maximum
Anode Voltage (max)AC Plate Voltage per Plate (max RMS, C-input filter)325V
Heater-to-Cathode Voltage (max)Max DC Heater-to-Cathode Potential450V
Voltage Drop (typical)Tube Voltage Drop (at 40 mA per plate)18
Notes
JEDEC base 6S — 6-pin Octal (pins 4 and 6 are unused). Uses the standard Octal socket with the same pinout as the 6X5/6X5-G/6W5-G family.
Tung-Sol datasheet (Feb 1940) states 40 mA max DC output with either condenser or choke input filter, and a tube voltage drop of 18 V at 40 mA per plate. Max AC plate voltage (RMS per plate) is 325 V with condenser input or 450 V with choke input; the more conservative 325 V figure is recorded in Va_max here.
Very low heater current (0.3 A) — about one-third that of the 6X5 family — makes this tube attractive for low-power receivers and small AC/DC sets where heater budget is tight.
Datasheet note: when filter capacitors larger than 40 µF are used, additional plate-supply impedance may be necessary to limit peak plate current.
Max heater-to-cathode potential is 450 V DC — on par with other 6.3 V indirectly-heated rectifiers.
Pin Layout — Octal
1No Connection
2Heater
3Anode 2 (Plate 2)
4
Socket-Compatible Tubes ⚠ Not electrically compatible