Tube cross-reference
EL821 alternatives, equivalents, and replacements
Review exact electrical variations and directional substitutions recorded for the EL821 power - pentode (not beam). Compare core specifications and verify every restriction before using a replacement.
Exact variations of EL821
These designations belong to the same electrical variation group. Their names may differ because of international standards, manufacturing tolerances, or materials, but they are recorded as electrically equivalent—not merely substitutes.
6CH6 Power - Pentode (NOT beam)
- Base
- 9BA
- Socket
- B9A
- Base pins
- 9
- Sections
- 1
- Heater voltage
- 6.3 V
- Heater current
- 0.75 A
Replacement tubes for EL821
The following tubes are recorded as possible replacements for EL821. This direction does not establish that EL821 can replace them.
Power - Pentode (NOT beam)
The database records 6CH6 as a possible replacement forEL821.
No special restrictions are recorded for this substitution.
| Specification | Original tube | Replacement |
|---|---|---|
| Tube type | Power - Pentode (NOT beam) | Power - Pentode (NOT beam) |
| Construction | Pentode | Pentode |
| Base | B9A | 9BA |
| Socket | B9A | B9A |
| Base pins | 9 | 9 |
| Sections | 1 | 1 |
| Heater voltage | 6.3 V | 6.3 V |
| Heater current | 0.75 A | 0.75 A |
Where EL821 can be used as the replacement
In these recorded relationships, EL821 is the replacement tube. The listed original tubes are not automatically suitable as replacements for EL821.
Voltage Pentode
The database records EL821 as a possible replacement for6132.
No special restrictions are recorded for this substitution.
| Specification | EL821 replacement | Original tube |
|---|---|---|
| Tube type | Power - Pentode (NOT beam) | Voltage Pentode |
| Construction | Pentode | Pentode |
| Base | B9A | 9BA |
| Socket | B9A | B9A |
| Base pins | 9 | 9 |
| Sections | 1 | 1 |
| Heater voltage | 6.3 V | 6.3 V |
| Heater current | 0.75 A | 0.145 A |
Power - Pentode (NOT beam)
The database records EL821 as a possible replacement for6CH6.
No special restrictions are recorded for this substitution.
| Specification | EL821 replacement | Original tube |
|---|---|---|
| Tube type | Power - Pentode (NOT beam) | Power - Pentode (NOT beam) |
| Construction | Pentode | Pentode |
| Base | B9A | 9BA |
| Socket | B9A | B9A |
| Base pins | 9 | 9 |
| Sections | 1 | 1 |
| Heater voltage | 6.3 V | 6.3 V |
| Heater current | 0.75 A | 0.75 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 EL821 specifications →