Tube cross-reference
DF91 alternatives, equivalents, and replacements
Review exact electrical variations and directional substitutions recorded for the DF91 voltage pentode or tetrode (under 100v). Compare core specifications and verify every restriction before using a replacement.
Exact variations of DF91
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.
1T4 Voltage Pentode or Tetrode (under 100V)
- Base
- 8AR
- Socket
- B7G
- Base pins
- 7
- Sections
- 1
- Heater voltage
- 1.4 V
- Heater current
- 0.05 A
Replacement tubes for DF91
The following tubes are recorded as possible replacements for DF91. This direction does not establish that DF91 can replace them.
Voltage Pentode or Tetrode (under 100V)
The database records 1T4 as a possible replacement forDF91.
No special restrictions are recorded for this substitution.
| Specification | Original tube | Replacement |
|---|---|---|
| Tube type | Voltage Pentode or Tetrode (under 100V) | Voltage Pentode or Tetrode (under 100V) |
| Construction | Pentode | Pentode |
| Base | B7G | 8AR |
| Socket | B7G | B7G |
| Base pins | 7 | 7 |
| Sections | 1 | 1 |
| Heater voltage | 1.4 V | 1.4 V |
| Heater current | 0.05 A | 0.05 A |
Where DF91 can be used as the replacement
In these recorded relationships, DF91 is the replacement tube. The listed original tubes are not automatically suitable as replacements for DF91.
Voltage Pentode or Tetrode (under 100V)
The database records DF91 as a possible replacement for1T4.
No special restrictions are recorded for this substitution.
| Specification | DF91 replacement | Original tube |
|---|---|---|
| Tube type | Voltage Pentode or Tetrode (under 100V) | Voltage Pentode or Tetrode (under 100V) |
| Construction | Pentode | Pentode |
| Base | B7G | 8AR |
| Socket | B7G | B7G |
| Base pins | 7 | 7 |
| Sections | 1 | 1 |
| Heater voltage | 1.4 V | 1.4 V |
| Heater current | 0.05 A | 0.05 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 DF91 specifications →