Lundahl LL1576 Audio transformer

The LL1576 is a high performance microphone input transformers/line-box transformers with high permeability mu-metal cores and high bandwidth coils. The LL1576 uses the same pin-out as our well known microphone transformer LL1538. In both types, primary and secondary windings are separated by electrostatic shields. The very low leakage inductance and thus excellent frequency response is achieved by a two-coil, three-section per coil winding structure. The transformers are encapsulated in mu-metal cases for magnetic shielding.

Turns ratio : 1 + 1 : 7

Technical Details:

• Dimensions Max. Length x Width x Height above PCB (mm)                                  38 x 24 x 17

• Spacing between pins                                                                                                  5.08 mm (0.2") 

• Spacing between rows of pins                                                                                     27.94 mm (1.1")

• Recommended PCB hole diameter                                                                              1.5 mm

• Weight                                                                                                                          46 g

• Static resistance of each primary                                                                                 50 ?

• Static resistance of secondary                                                                                      1.5 k?

• Primary level at 0.2 % THD, 50 Hz signal Primaries connected                                +2 dBU (sec. level +19 dBU)

          in parallel (fig b), source impedance 50?

• Primary level at 1 % THD, 50 Hz signal Primaries connected in                               + 12 dBU (sec. level +29 dBU

          parallel (fig b), source impedance 50?

• Frequency response +/- 0.5 dB to balanced input Signal level 0 dBU,                       15Hz – 50kHz

          source 200 ?, fig b, no termination

• Frequency response +/- 0.5 dB to balanced input Signal level -10 dBU,                    5Hz – 40kHz 30 k? + 200pF

          source 50 ?, fig b, load:

• Isolation between windings / between windings and shield                                        4 kV / 2 kV