Power - Triode ·Triode
Higher-rated directly heated 2A3-family audio power triode for Class A output stages. Increased plate-voltage and dissipation capability extends the traditional 2A3 operating range, with published conditions reaching roughly 9 W output.
Solid-plate directly heated 2A3 replacement audio triode with enhanced power capability. The supplied Emission Labs sheet was read for filament data, maximum ratings, representative operating points, gm/rp/mu, output conditions, capacitances, and rectifier filter conditions as applicable.
Medium-shell UX 4-contact
General specifications
Properties common to every published source and operating point.
Electrical assignments shared by every tube using this base designation.
No verified pinout is recorded for this base designation.
1 physical section, each with unique specifications.
Section 1
Source-dependent data
Each block preserves the test conditions and published values from one reference. Values from different sources are intentionally kept separate.
Data set 01
Published operating points and test conditions from this source.
Filament voltage
2.5 V
Filament current
2.5 A
Plate resistance
800 ohm
ClassA
Amplification factor
4.1
ClassA
Transconductance
5200 uS
ClassA
Plate voltage
250 V
ClassA
Plate current
60 mA
ClassA
Grid voltage
-45 V
ClassA
Load resistance
2500 ohm
ClassA
Output power
3.5 W
ClassA
High-power output power
9.3 W