LL2774: Lundahl Headphone Output Transformer

The LL2774 is available in 3 options to suit the circuit topology. (The air-gap is adjusted during manufacture to suit)

• Push-Pull
• 30mA Single-ended
• 60mA Single-ended

(N.B. The purpose of the airgap is to accept the DC current of the output valve without saturating the core, leaving enough headroom for the sound signal)

There are further 2 options depending on what C-core material you require.

• Silicon-iron (STANDARD)
• Amorphous-iron (AM)

Turns ratio

• 6.8+6.8 : 1+1+1+1

Depending on how the winding sections of the transformers are wired together via the exposed solder pins, the constructor can adjust the following primary and secondary impedances.

Primary impedance (load): Secondary impedance (headphone impedance) with turns ratio

• 3K:16R, 13.6:1
• 3K:64R, 6.8:1
• 3K5:300R, 3.4:1

For more information on this product, please click HERE