Lundahl Moving coil input transformer, LL9206

Audio Transformer/Moving Coil Input Transformer LL9206

LL9206 is an input audio transformer for moving coil pickups. The transformer is built up from two coils, each coil with one secondary winding surrounded by two primary windings. This structure results in an excellent frequency response. All winding ends are available on the pins. Thus, the transformer can be used with a set of different turns ratios. The LL9206 is made with amorphous core material. As this type of core does not store energy (unlike e.g. conventional mu-metal cores) the low frequency resonance with external series capacitors is practically eliminated.

Turns ratio: 1 + 1 + 1 + 1 : 10 + 10
Dims: (Length x Width x Height above PCB (mm)) 30 x 22.5 x 14.5

Spacing between pins: 2.54 mm (0.1")
Spacing between rows of pins: 22.86 mm (0.9")
Weight: 27 g
Rec. PCB hole diameter: 1.5 mm
Static resistance of each primary (average): 10 ?
Static resistance of each secondary (average): 395 ?
Self resonance point : > 250 kHz
Frequency response (@ -10 dBU, all in series. Source 50? , load 100 k?):

10 Hz -- 25 kHz +/- 1 dB
10 Hz -- 90 kHz +/- 1.5 dB

Distortion (primaries connected in series, source impedance 50? ): < 0.5% @ -2 dBU, 50 Hz
Primary no load impedance @ 0 dBU, 50 Hz, all in series: 8 k? typically
Core / Can: Amorphous Strip Core / Mu metal can
Isolation between windings / between windings and core: 3 kV / 1.5 kV

When the LL9206 is used in MC pickup applications, please note that the primary side of the transformer must have a ground reference.