LL2766: Lundahl Output Transformer

The Lundahl LL2766 small-sized C-core output transformers for tube amplifiers have a primary impedance of 3K or 6K with secondary impedances of 4R, 8R or 16R, depending on how you wire them up. There are options for circuit topology and core material, which you select when you purchase.

The transformer has a special high flux, low distortion audio C-core of Lundahl`s production. The LL2766PP is assembled with a small core air gap to allow for some DC current unbalance. For the S.E. versions of the LL2766, the core air gap is chosen such that the denoted DC current (50mA for a LL2766/50mA) generates a no signal core flux density of 0.9 Tesla when used with all primaries in series. This leaves a flux density swing of 0.7 T for the signal.

The transformers are of an open frame type and are suitable for mounting inside an amplifier housing.

The LL2766 is available in 3 versions. (The air-gap is adjusted during manufacture to suit)

• Push-Pull
• 30mA Single-ended
• 50mA 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 versions depending on what C-core material you require.

• Silicon-iron
• Amorphous-iron (AM)

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: Secondary impedance

• 6K: 4R, 8R or 16R
• 3K: 4R, 8R or 16R

Overall dimensions including pins - 73mm x 61mm x 53mm

STARTING PRICE (1 off)
£104.67 +vat +p&p

Non-Stock Item - Please allow 4-6 weeks for dispatch