Lundahl LL1663-50 Output Transformer for Tube Amplifiers 50mA

The Lundahl LL1663-50 is a 50 mA tube amplifier output transformer with a 5 kΩ to 8 Ω impedance ratio, built around a four-section dual-coil C-core construction for single-ended and push-pull amplifier use.

Highlights of the Lundahl LL1663-50

• 5 kΩ to 8 Ω impedance ratio for tube amplifier output stages
• Four-section dual-coil C-core construction
• 50 mA version with 8 W maximum output power at 30 Hz into an 8 Ω speaker
• Turns ratio of 12+12:1 or (4+8)+(4+8):1
• High internal isolation with isolation foil between each copper layer
• 4 kV isolation between windings and 2 kV between windings and core

Product details Lundahl LL1663-50

Lundahl LL1663-50 Output Transformer for Tube Amplifiers 50mA 5k:8 Ohms

The Lundahl LL1663-50 is designed for tube amplifiers requiring a 5 kΩ primary to 8 Ω secondary impedance ratio. It belongs to the LL1663 output transformer series and is suitable for both single-ended and push-pull configurations, with connection options for plate-to-plate operation and 33% ultra-linear taps.

Its four-sectioned dual-coil C-core design makes it a serious choice among high-quality audio components for amplifier construction. The winding uses Lundahl’s high internal isolation technique, with isolation foil placed between each copper layer, while the core is an audio C-core produced by Lundahl.

For the 50 mA version, the transformer supports a maximum primary signal of 200 V RMS at 30 Hz and delivers up to 8 W at 30 Hz into an 8 Ω speaker. The turns ratio is 12+12:1 or (4+8)+(4+8):1, giving builders flexible wiring options for the intended output stage topology.

Key electrical details include 102 Ω static resistance for each primary winding, 0.4 Ω static resistance on the secondary, and isolation ratings of 4 kV between windings and 2 kV between windings and core. The transformer weighs 1.35 kg and uses four M4 mounting holes for installation.