Lundahl Tube amplifier output transformer, LL2735B

Tube amplifier output transformer LL2735B 16k : 8 ohms

The LL2735B is a tube amplifier output transformer for 16k : 8 ohms impedance ratio, primarily designed for for high rp tubes such as 10Y, 801A and EML20B in single-end applications. The transformer is a dual coil transformer where coils are wound using our high internal isolation technique with isolation foil between each layer of copper wire. Each coil consist of one primary and two secondary sections. The isolation between primary and secondary sections are gradually increased closer to the tube anode connection in order to minimize capacitive energy storage.

The core is a silicon-iron audio C-core of our own production.

Turns ratio 23 + 23 : 1

Weight: 1.35 kg
Static resistance of each primary: 270 ?
Static resistance of secondary: 0.2 ?
Isolation between windings / between windings and core: 4 kV / 2 kV
Max DC current through any primary winding: 100 mA (6W heat power)

Primary inductance: 90H
Max primary signal: 300V rms @ 30Hz
Max output power @ 30 Hz, Loudspeaker impedance 8 ohm: 5 W