Lundahl Line input transformer, LL1592

High Level Line Input Transformer LL1592

LL1592 is a high-level line input transformer with a mu metal lamination core. The transformer is designed for high end pro audio line input applications with or without phase splitting. The windings are arranged to give a high degree of symmetry if the transformer is used for phase splitting. The dual-coil structure also greatly improves immunity to external magnetic fields from e.g. power supplies and motors. Primary and secondary windings are separated by electrostatic shields. The transformer is housed in a mu-metal can.

Turns ratio: 1 + 1 : 1 + 1

Dimensions (L x W x H above PCB, in mm) 47 x 28 x 20
Spacing between pins 5.08 mm (0.2")
Spacing between rows of pins 35.56 mm (1.4")
Rec. PCB hole diameter: 1.5 mm
Weight: 83 g
Static resistance of each primary: 270 ?
Static resistance of each secondary: 270 ?

Distortion + 23 dBU 0.1% @ 40 Hz
(primaries connected in series, source impedance 600?): + 29 dBU < 1 % @ 40 Hz

Self resonance point: > 120 kHz
Suggested termination for best square wave response, serial-serial connection: 7k + 400pF
Frequency response (serial connection, source 600 ?, load 20 k?, no terminating network) 10 Hz -- 50 kHz +/- 1.0 dB
Frequency response (serial connection, source 600 ?, load 100 k? in parallel with 7k + 400pF): 10 Hz -- 100 kHz +/- 1.0 dB
Phase splitting balance (connection 2:1+1. Source 1k?, load (20k? +20k?) in parallel with 7k + 400pF): >46 dB, 10Hz 50kHz
Phase response (deviation from linear phase) (source 600 ohm, load 10k (Audio Precision): 10 Hz 20kHz, < 2

Isolation between windings/ between windings and shield: 3 kV / 1.5 kV