Lundahl Low cost audio isolation transformer, LL1591

Low cost audio isolation transformer LL1591

LL1591 is a low cost audio isolation transformer, pin compatible with e.g. LL1527 and LL1581XL. The purpose with LL1591 is to provide a low cost solution, when noise rejection requirements are small. The LL1591 does not have internal faraday shields, nor mu metal housing.

Turns ratio: 1 + 1 : 1 + 1
Spacing between pins 5.08 mm (0.2")
Spacing between rows of pins 27.94 mm (1.1")

Dimensions: (L x W x H above PCB, in mm) 37 x 22 x 17
Weight: 39 g
Rec. PCB hole diameter: 1.5 mm
Static resistance of each primary: 43W
Static resistance of each secondary: 55W
Distortion (primaries connected in series, source impedance 800W): + 6 dBU 0.1% @ 50 Hz +16 dBU < 1 % @ 50 Hz
Self resonance point : > 120 kHz
Optimum load for best square-wave response (sec. in series): 3 4 kW
Frequency response (source 600W , load 10 kW serial connection): 10 Hz -- 80 kHz +/- 1 dB
Loss across transformer (at midband, with above termination): 0.4 dB
Isolation between windings/ between windings and core: 3 kV / 1.5 kV