Lundahl LL1688

The LL1688 is an output transformer designed primarily for 845 tube amplifiers, though it's also offered with different core air gaps for other output-stage types. Heavy sectioning with harmonically proportioned sections keeps leakage inductance to a minimum, and combined with a low-capacitance winding technique, this delivers a wide frequency range. The primary can be tapped for a 33% UL connection. It uses a special, in-house-made audio C-core and comes as an unpotted, open-frame unit for mounting inside an amplifier chassis.

Lundahl transformers are mainly used in the output/interstage of tube amplifiers, in microphone and line inputs, and for galvanic isolation in studio and live sound systems (DI boxes, ground-loop breakers). The Swedish manufacturer winds its own copper wire and casts its own cores for every model, resulting in very consistent, factory-measured parameters even in series production. For custom loudspeaker or amplifier builds, tube amp restorations, or premium DI box projects, Lundahl transformers provide a reference-quality foundation, and most output types are available for both push-pull and single-ended (SE) stages. The brand has earned the trust of major names across the audio industry - studios, instrument and amplifier makers - over several decades, and many designers build their circuit specifically around a Lundahl transformer because the catalogue parameters (inductance, leakage inductance, DC resistance, saturation level) are reliably reproducible from unit to unit. Before installing, it is worth double-checking the exact impedance match and the available mounting space, since size and weight can vary significantly between types.

Swedish manufacturer Lundahl Transformers AB has been hand-winding custom iron-core audio transformers for more than half a century, used by leading tube amplifier designers and studios worldwide for reference-quality signal transfer.

Package weight: approx. 4,5 kg.