IWISTAO 50W 1 Piece Push-Pull Tube Amplifier Output Transformer Z11 EI Core 5.5KΩ / 6KΩ for 2A3 300B KT88 KT66 EL34 6L6

IWISTAO 50W 1 Piece Push-Pull Tube Amplifier Output Transformer Z11 EI Core 5.5KΩ / 6KΩ for 2A3 300B KT88 KT66 EL34 6L6 Model No: WHFTR-PPOPT5K50W The IWISTAO 50W Push-Pull Output Transformer is designed for high-quality DIY vacuum tube power amplifiers using popular output tubes such as 2A3, 300B, KT88, KT66, EL34, 6CA7, 6L6, and 5881. Built around a large 96 × 50 mm laminated EI core using Japanese Z11 0.35 mm silicon steel, the transformer is engineered for excellent low-frequency power handling, wide bandwidth, low insertion loss, and stable push-pull operation. With a rated continuous output of 50W at 30Hz, it is particularly suitable for serious Hi-Fi tube amplifier projects where output transformer bandwidth and core capacity are critical to overall sound quality. Four Options Option Primary Impedance Insulation Material Frequency Response 50-A Standard 5.5KΩ Japanese Miki Insulation Paper 3Hz–75kHz (-3dB) 50-A DuPont 5.5KΩ USA DuPont Insulation Paper 3Hz–75kHz (-3dB) 50-B Standard 6KΩ Japanese Miki Insulation Paper 3Hz–62kHz (-3dB) 50-B DuPont 6KΩ USA DuPont Insulation Paper 3Hz–62kHz (-3dB) The 50-A version uses a 5.5KΩ primary, while the 50-B version uses a 6KΩ primary, allowing the transformer to accommodate different tube types, operating points, and push-pull amplifier designs. The DuPont versions use upgraded USA DuPont insulation paper in place of the standard Japanese Miki insulation paper. Key Features 50W continuous output power at 30Hz Designed for push-pull vacuum tube amplifiers Suitable for 2A3, 300B, KT88, KT66, EL34, 6CA7, 6L6, 5881, and similar tubes Primary impedance options: 5.5KΩ or 6KΩ Secondary output: 0–4Ω–8Ω Japanese Z11 0.35mm silicon steel EI laminations Large 96 × 50mm stacked core Imported British oxygen-free copper winding wire Japanese Miki insulation paper as standard (Optional upgraded USA DuPont insulation paper) Wide-bandwidth design Vertical mounting with side covers Approx. 3kg per piece Specifications 1. Rated Output Power: 50W continuous at 30Hz 2. Primary Impedance: 50-A: 5.5KΩ or 50-B: 6KΩ 3. Secondary Impedance: 0–4Ω–8Ω (Other impedance configurations may be available upon request). 4. Core Material: Japanese Z11 silicon steel, 0.35mm laminations 5. Core Size: 96 × 50mm EI laminated stack 6. Winding Wire: Imported British oxygen-free copper 7. Standard Insulation: Japanese Miki insulation paper Optional Insulation: USA DuPont insulation paper 8. Frequency Response – 50-A:3Hz–75kHz, -3dB Frequency Response – 50-B: 3Hz–62kHz, -3dB (Frequency response measured with a 300B tube in-circuit, referenced to 0dB at 1kHz into an 8Ω load). 9. Mounting Style: Vertical mounting with side covers 10. Weight: Approx. 3kg / piece 11. Sizes: Applications This transformer is suitable for custom and DIY push-pull tube power amplifiers, including designs based on 300B, 2A3, KT88, KT66, EL34, 6CA7, 6L6, and 5881 output tubes. The combination of a large Z11 EI core, oxygen-free copper windings, high primary-current capability, and wide frequency response makes it particularly suitable for Hi-Fi amplifier projects requiring strong low-frequency performance, good transient response, and extended high-frequency bandwidth. Package / Ordering Note The displayed price is for ONE output transformer. For a stereo amplifier, please order 2 pieces. An optional black resin-potted square cover is also available at additional cost.