Description
LUNDAHL ANALOGUE AUDIO TRANSFORMERS
A range of high performance PCB mounting analogue audio transformers, manufactured in Sweden. Lundahl will design variations on existing types, or completely new constructions, to meet specific needs. All housing cans are mu-metal, and pin diameters are 1.1mm, recommended PCB drill 1.5mm.
Full data and application notes for each type are available from the Lundahl website at www.lundahl.se, or from Canford Technical Support.
New designs
LL1581XL Splitting transformer
In many splitting applications, the transformer must have a high immunity to common mode signals, to stray magnetic fields from eg. power transformers, and to large potential differences in receiving systems. This transformers uses Lundahl’s well established two coil structure to create a transformer with a high degree of symmetry. It is built up from two primary windings (which should be used in parallel) and two secondary windings. Each secondary winding is built up from two sections, one from each coil, and a separate electrostatic shield surrounds each secondary section. This symmetric structure results in an internal cancellation of noise signals caused by external magnetic fields. It also increases immunity to ground noise between secondary systems and reduces the effect of input common mode signals. The transformer is designed so that a “direct” split can be connected in parallel across the input windings. Turns ratio 1:1+1. Dimensions: 38(l) x 24(w) x 20.5(h above PCB)mm. Weight: 61g.
LL1587 Mic transformer
A small sized mic input transformer, with a high permeability mu-metal core and two two-section coils with internal Faraday shields. Turns ratio 1+1:4. Dimensions: 26(l) x 17(w) x 12(h above PCB)mm. Weight: 18g.
LL1588 High level general purpose transformer
This can be used for mic or line input, for line output, or for galvanic isolation. The windings are arranged to give perfect symmetry if the transformer is used in phase splitting input applications. The two coils structure also greatly improves the immunity to external magnetic fields from eg. power supplies and motors. Primary and secondary windings are separated by electrostatic shields. Turns ratio 1+1:1+1. Dimensions: 47(l) x 28(w) x 24(h above PCB)mm. Weight: 115g.