Lundahl LL1660-10 Interstage Transformer for Tube Amplifiers 10mA

The Lundahl LL1660-10 is a 10 mA interstage and line output transformer for tube amplifier designs, built with a low-capacitance winding technique and Lundahl’s high-flux, low-distortion audio C-core.

Highlights of the Lundahl LL1660-10

• Interstage and line output transformer for tube amplifiers
• 10 mA single-ended version with dedicated core air gap
• Special low-capacitance winding technique for high-frequency performance
• High-flux, low-distortion audio C-core construction
• Multiple connection alternatives for SE-to-SE, SE-to-PP and line output use
• 4 kV primary-to-secondary isolation and 2 kV winding-to-core isolation

Product details Lundahl LL1660-10

Lundahl LL1660-10 Interstage / Line Output Transformer for Tube Amplifiers 10 mA

The Lundahl LL1660-10 is designed for use in tube amplifier circuits as an interstage transformer or line output transformer. As a precision audio component, it uses a special low-capacitance winding technique to support extended high-frequency performance in demanding valve audio designs.

This 10 mA single-ended version uses a selected core air gap so that the denoted DC current generates a no-signal core flux density of 0.9 Tesla when all primaries are used in series. This leaves room for a 0.7 Tesla signal flux density swing, making the LL1660-10 suitable for carefully designed amplifiers where transformer behavior is critical to the circuit.

The transformer offers several connection alternatives. In single-ended to single-ended interstage configuration, the LL1660-10 supports a 4:4.5 ratio with 130 H primary inductance, 25 Hz to 40 kHz frequency response and up to 250 V r.m.s. output at 30 Hz. Alternative 2:4.5 and 2.25:2+2 configurations are available for SE-to-SE and SE-to-push-pull interstage use.

Built around Lundahl’s own high-flux, low-distortion audio C-core, the LL1660-10 weighs 0.75 kg and provides robust electrical isolation: 4 kV between primary and secondary windings and 2 kV between windings and core. With a maximum current of 50 mA through any single section, it is a specialist transformer for advanced tube amplifier builds and related amplifier accessories work.