ZXY EE25-1:1A Audio Transformer, EE25 Series 1:1 Turns Ratio, Ferrite Core, Through-Hole PCB Mount, 25.5 x 18.5 x 22.0 mm, 5.0 mm Pin Pitch

1. Product Name

ZXY EE25-1:1A audio transformer, EE25 series, 1:1 turns ratio. High-frequency ferrite core held in a metal frame, PA66 bobbin, vertical through-hole PCB mounting, 5.0 mm pin pitch, body dimensions 25.5 x 18.5 x 22.0 mm, primary pins 1-4, secondary pins 5-8.

Overview. The transformer stands upright on the circuit board: two rows of four pins each, 12.5 mm apart, with the body rising 22.0 mm above the copper surface. Its footprint is 25.5 × 18.5 mm, allowing it to fit between adjacent components in high-density layouts.

The core is a pair of EE25 ferrite cores clamped within a metal frame. Securing the core inside the frame rather than leaving it loose ensures the air gap remains fixed during handling, insertion, and soldering, while also protecting the core edges during assembly.

2. Product Features

1:1 turns ratio, 1:1A version. The primary and secondary windings have the same number of turns, making it suitable for applications where identical impedance is required on both sides of the circuit.

Precision copper wire winding. Automated equipment winds the coils to a precise 1:1 ratio, ensuring batch-to-batch consistency that does not depend on operator skill.

High-frequency ferrite core in a metal frame. The core is held in the frame rather than left loose, maintaining a closed magnetic path and protecting the core during handling and assembly.

Durable PA66 bobbin. Polyamide 66 material carries the molded pin terminal block, holding pins in position for insertion and withstanding soldering temperatures.

Vertical through-hole mounting. Straight pins with a 5.0 mm pitch conform to standard PCB layouts and support hand or wave soldering.

Compact footprint. 25.5 mm × 18.5 mm, with a total height of 22.0 mm — the component stands up on the board rather than spreading horizontally.

Laser-etched marking. The model code is etched rather than printed on a sticker, maintaining legibility over the product lifetime and supporting production traceability.

Tape-wrapped insulation. Tape isolates the winding from the core, and the terminal pins are tin-plated.

The four annotated points are the four items to inspect upon incoming receipt: the etched code, the winding, the bobbin, and the core. The code should read EE25-1:1A, the winding should be even and tight with the tape wrap intact, the pin block should be complete and undamaged, and the frame should close around the core without visible gaps.

3. Product Advantages

Repeatable consistency. Precision winding equipment produces matched 1:1 windings, ensuring every unit is identical — especially important where the transformer is the measured component in a signal chain.

Stable magnetic circuit. The core is held in the frame, so the air gap does not shift during handling, maintaining consistency without potting.

Standard 5.0 mm pitch. Directly fits standard PCB layouts, supports hand or wave soldering, and requires no carrier tape.

PA66 bobbin. Combines mechanical strength and heat resistance, with pins molded into precise position for reliable insertion.

Clear marking. Laser etching lasts longer than printed labels over the service life.

Complete compliance documentation. ISO 9001:2015 certification and CE declaration of conformity under the Low Voltage Directive are provided with certificate numbers, satisfying end-product technical file requirements.

One production line, multiple models. The same certified production line covers the entire ZXY transformer range, allowing multiple model types to be purchased in a single order.

The winding schematic serves as the wiring reference: pin 1 is the primary polarity dot, and pin 5 is the secondary polarity dot. Reversing either winding will not cause the transformer to fail, but it will invert the signal phase — critical when two channels must remain in phase.

4. Applications

Audio signal isolation and coupling. Used between amplifier stages and within audio equipment circuits.

Galvanic isolation. Provides isolation between circuit stages, between boards, or between separate audio devices.

Impedance matching. Suitable for applications where primary and secondary impedances are equal, as well as balanced-to-unbalanced conversion in audio signal paths.

Ground loop elimination. Isolation removes AC hum caused by two devices at different ground potentials.

PCB-mount audio circuits. Fits consumer and professional audio equipment.

In all of the above applications, the transformer performs the same function: passing the signal while breaking the connection between the two grounds. A 1:1 device achieves this without changing the level, so it appears at inter-stage interfaces rather than inside the amplifier itself.

5. Application Specifications

The following specifications are the published construction, wiring, and dimensional data for this model.

5.1 Product Specifications

5.2 Construction and Mechanical Data

5.3 Winding Terminals