Tube cross-reference
1603 alternatives, equivalents, and replacements
Review exact electrical variations and directional substitutions recorded for the 1603 voltage pentode - sharp cutoff (single). Compare core specifications and verify every restriction before using a replacement.
Replacement tubes for 1603
The following tubes are recorded as possible replacements for 1603. This direction does not establish that 1603 can replace them.
Voltage Pentode
The database records 6C6 as a possible replacement for1603.
No special restrictions are recorded for this substitution.
| Specification | Original tube | Replacement |
|---|---|---|
| Tube type | Voltage Pentode - Sharp Cutoff (single) | Voltage Pentode |
| Construction | Pentode | Pentode |
| Base | Not recorded | 6F |
| Socket | UX6 | UX6 |
| Base pins | 6 | 6 |
| Sections | 1 | 1 |
| Heater voltage | 6.3 V | 6.3 V |
| Heater current | 0.3 A | 0.3 A |
Verify before substituting
Matching a base or heater voltage is not enough to prove that two tubes are interchangeable. Check pin connections, heater current, maximum ratings, bias requirements, warm-up behavior, and the equipment manufacturer’s service documentation before making a substitution.
View the complete 1603 specifications →