Lundahl LL2752-PP Output Transformer for Tube Amplifiers Push-Pull

The Lundahl LL2752-PP is an open-frame tube amplifier output transformer designed for push-pull applications, with a primary focus on 2 kΩ to 8 Ω operation, high sectioning, low leakage inductance and wide frequency response.

Highlights of the Lundahl LL2752-PP

• Output transformer for tube amplifier push-pull designs
• Primarily designed for 2 kΩ to 8 Ω applications
• Highly sectioned winding structure for minimum leakage inductance
• Low-capacitance coil winding technique for wide frequency range
• Open-frame, un-potted construction for mounting inside amplifier housings
• Lundahl silicon iron C-core, also available with amorphous C-core

Product details Lundahl LL2752-PP

Lundahl LL2752-PP Output Transformer for Tube Amplifiers Push-Pull

The Lundahl LL2752-PP is built for tube amplifiers where a robust, wide-band output transformer is required. It is primarily intended for 2 kΩ to 8 Ω applications and uses a 12+12+12+12 : 2+1+1+2+1+1 turns ratio, giving designers flexible primary and secondary connection options.

Its highly sectioned construction uses harmonically sized sections to minimize leakage inductance. Combined with Lundahl’s low-capacitance coil winding technique, this helps the LL2752-PP deliver a wide frequency range. For the LL2752/60mA version, frequency response reaches 10 Hz to 50 kHz at +0/-1 dB with secondary connection C.

The transformer is an un-potted, open-frame type suitable for installation inside amplifier housings and custom audio components. It uses a Lundahl silicon iron C-core and weighs 2.5 kg. Mechanical details include an approximate row spacing of 75 mm, 5.08 mm primary-side pin spacing, approximately 7 mm secondary-side pin spacing and four M4 mounting holes.

For push-pull operation, the LL2752 supports a maximum primary signal voltage of 480 V RMS at 30 Hz with all primary sections in series. Primary load impedance options include 4.6 kΩ, 2 kΩ and 1.2 kΩ depending on the secondary connection, with maximum push-pull power ratings at 30 Hz of 45 W, 105 W and 180 W respectively. Isolation is rated at 3 kV between primary and secondary windings and 1.5 kV between windings and core.