Lundahl LL1664-PP Output Transformer for Tube Amplifiers Push-Pull

Highlights of the Lundahl LL1664-PP

• Push-pull output transformer for 3 kΩ plate-to-plate impedance with an 8 ohm load
• Four-sectioned dual coil C-core design
• High internal isolation with isolation foil between each copper layer
• 55 W maximum output power at 30 Hz with an 8 ohm speaker
• 33% ultralinear taps for push-pull tube amplifier applications

Product details Lundahl LL1664-PP

Lundahl LL1664-PP 3 kΩ:8 ohms Push-Pull Tube Amplifier Output Transformer

The Lundahl LL1664-PP is designed for push-pull tube amplifiers, providing a 3 kΩ plate-to-plate primary impedance when used with an 8 ohm load. Its turns ratio is 9.6 + 9.6:1, with alternative primary winding sections of (3.2 + 6.4) + (3.2 + 6.4):1 for flexible implementation.

At the heart of this audio component is a four-sectioned dual coil C-core. Lundahl’s high internal isolation technique uses isolation foil between each copper layer, while the audio C-core is made in-house by Lundahl. This construction supports reliable operation in high-voltage tube amplifier circuits.

For the LL1664-PP version, primary inductance is approximately 35 H, with a maximum primary signal level of 410 Vrms at 30 Hz. Maximum output power is 55 W at 30 Hz into an 8 ohm speaker. The transformer also includes 33% ultralinear taps for UL push-pull designs.

Key electrical specifications include 74 Ω static resistance for each primary, 0.5 Ω static resistance on the secondary, 8 mH primary leakage inductance with primaries in series, and maximum DC current of 200 mA through any primary winding. Isolation is rated at 4 kV between windings and 2 kV between windings and core. The transformer weighs 1.35 kg and uses 4 x M4 mounting holes.