▼ Menu

    
Extras ▼

The DA41 is a magnificent audio triode that was designed for high power use. In class B a pair would deliver 175 Watts at 5% distortion. The anode dissipation is 40 Watts.

The data-sheet places the valve as from 1954 but this could be just for the carbon anode version.

Our other DA41 has a carbon anode whereas this exhibit has a pressed metal anode. The other exhibit also has a ceramic base that would offer better insulation in high humidity.

The anode is rectangular and the active anode surfaces are the broad faces.

The formation of the anode by pressing from two sheets of nickel can be seen as can the filament tension springs and the close spaced grid. The grid wires being held in notched support rods.

A closer view of the top of the electrodes. The filament is thoriated tungsten.

The balloon envelope is 51 mm in diameter and, excluding the UX4 base pins, is 139 mm tall.

References: Data-sheet, ¹⁰⁴⁰ & ¹⁰⁴³. Type DA41 was first introduced in 1939. See also 1939 adverts.

Pin Connections

Absolute Maximum Operating Conditions^¶

Thanks to Frank Philipse for supplying the above PDF datasheet.