5C3S — Rectifier, Octal | Tubeofile | Tubeofile

5C3S

Rectifier — DHT — Octal

Data: HighHigh quality — base, heater, all universal parameters present, and ≥50% of desirable parameters filled in. Safe to use for design decisions.

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Known Equivalents & Substitutes

5AS4A

Similar Tubes (Not Drop-In Compatible)

5U4G

Western functional equivalent with same Octal base — verify heater current compatibility (5C3S draws 3.0A vs 5U4G at 3.0A)

5Y3GT

Lower-current rectifier on same Octal base (125 mA vs 225 mA) — not a direct replacement in higher-current circuits

GZ31

Philips/Mullard equivalent — same Octal base but verify pinout compatibility

Electrical Specifications

Absolute Maximum

Anode Voltage (max)AC Voltage per Plate (max RMS)450V

Rectifier

Peak Inverse VoltagePeak Inverse Voltage1,550V

Voltage Drop (typical)Voltage Drop (typical)44V

Max C-input Filter CapacitorMax C-input Filter Capacitor40µF

Notes

5Ц3С (5Ts3S) is the Cyrillic designation. The Latin transliteration is 5C3S.
Directly heated (filament cathode) — observe heater warm-up time before applying B+.
Russian equivalents reference lists Western equivalents as 5AS4A, 5U4G, GZ31.
Commonly found in Soviet audio amplifiers and radio equipment as the primary rectifier tube.
Same Octal base and pinout as 5U4G — widely used as a substitute in Western amplifier restorations.

Pin Layout — Octal