Lundahl LL1588 High Level General Purpose Transformer

Highlights of the Lundahl LL1588

• High-level general-purpose transformer for microphone input, line input, line output and galvanic isolation
• 1+1:1+1 turns ratio with flexible serial and parallel connection options
• Two-coil structure for improved immunity to external magnetic fields
• Electrostatic shields between primary and secondary windings, housed in a mu-metal can

Product details Lundahl LL1588

Lundahl LL1588 High Level General Purpose Transformer 1+1:1+1

The Lundahl LL1588 is built for high-level audio signal applications where reliable isolation and flexible wiring are important. It can be used for microphone or line input, line output and galvanic isolation, making it a versatile choice for line-level interfaces in audio components and signal stages used around amplifiers.

The winding arrangement is designed for excellent symmetry, especially when the transformer is used in phase-splitting input applications. Its two-coil structure also improves immunity to external magnetic fields from nearby power supplies, motors and other interference sources. Primary and secondary windings are separated by electrostatic shields, while the high-permeability mu-metal core is enclosed in a mu-metal can.

Performance is well suited to demanding high-level audio circuits. With primaries connected in series and a 150 Ω source impedance, distortion is 0.1% at +25 dBu and below 1% at +28 dBu, measured at 50 Hz. In serial connection with a 150 Ω source and 10 kΩ load, frequency response extends from 10 Hz to 100 kHz within ±1.0 dB, with phase response deviation of ±0.5° from 20 Hz to 20 kHz.

The LL1588 is intended for PCB mounting, with dimensions of 47 x 28 x 24 mm above the PCB and a weight of 115 g. Pin spacing is 5.08 mm, row spacing is 35.56 mm and the recommended PCB hole diameter is 1.5 mm. Connection alternatives include parallel-parallel 1:1 wiring for low-loss isolation, serial-serial 1:1 wiring for high-level line isolation and phase-splitting 1:1+1 input use.