ZXY-EE25 Flying-Lead Audio Isolation Transformer - 1:4 Turns Ratio | 65mH/900mH Inductance | AC 500V Isolation | CCC CE RoHS UL

1. Product Overview

The ZXY-EE25 is a compact audio isolation transformer featuring a high-grade EE25 silicon steel core and multi-color lead terminations. With a 1:4 turns ratio, inductance ranging from 65 mH to 900 mH at 1 kHz, and pre-stripped, tin-plated lead ends, it delivers impedance matching, electrical signal isolation, and ground loop noise suppression in professional audio, broadcast, communication, and industrial audio equipment.

Figure 1 — EE25 flying-lead audio isolation transformer with multi-color leads and tin-plated copper terminations.

Overview

Parameter	Value
Turns Ratio	1 : 4
Inductance (Red–Blue)	Typ. 900 mH (Min. 800 mH) @ 1 kHz
Inductance (Yellow–Green)	Typ. 65 mH (Min. 56 mH) @ 1 kHz
DC Resistance (DCR)	1.55 Ω / 17.5 Ω (±10%)
Dielectric Withstanding Voltage (Hi-Pot)	AC 500 V / 2 mA / 3 s, no breakdown
Insulation Resistance	≥ 100 MΩ @ 500 V DC
Dimensions (L × W × H)	26.0 × 19.0 × 14.8 mm

2. Key Features

• High-Grade EE25 Core Frame — Premium silicon steel core with low loss, high efficiency, and stable performance.
• Multi-Color Flying Leads — Five color-coded leads (black, white, red, yellow, green) for easy identification and reliable connection.
• Pre-Stripped Tin-Plated Copper Ends — Ready for direct soldering, enabling fast and reliable installation.
• Flame-Retardant Nylon Bobbin — Made of high-temperature UL94V-0 material for enhanced safety and durability.
• High-Purity Enameled Copper Wire — 0.025–2.0 mm winding wire for consistent signal transmission and low distortion.
• Class B/F High Dielectric Insulation — Reliable AC 500 V dielectric isolation between windings.
• 26.0 × 19.0 × 14.8 mm Footprint — Compact size suitable for high-density PCB and chassis layouts.

Figure 2 — Key structural features of the EE25 flying-lead transformer.

Figure 3 — Winding wire, dielectric insulation, core, and bobbin materials.

3. Advantages

• Precise 1:4 Turns Ratio — Stable 65 mH / 900 mH inductance at 1 kHz for repeatable impedance matching.
• Low Winding Resistance — DCR of only 1.55 Ω / 17.5 Ω minimizes insertion loss and preserves signal levels.
• Faithful Audio Transmission — Flat frequency response and low harmonic distortion across low-frequency and audio ranges make the EE25 ideal for high-fidelity signal paths.
• Galvanic Isolation — AC 500 V, 50 Hz withstand voltage breaks ground loops and blocks common-mode noise between equipment stages.
• Stable Insulation — Insulation resistance ≥ 100 MΩ at 500 V DC supports long-term reliability.
• Certified Quality — UL-certified leads, CCC / CE / RoHS / UL compliance, and ISO 9001:2015 production system.

Figure 4 — Audio-grade electrical performance and dielectric withstand voltage.

4. Application Areas

Core Functions: Impedance Matching · Signal Isolation · Noise Suppression (Ground Loop) · Balanced/Unbalanced Conversion

• Professional Audio/Video Equipment — Tube amplifiers, DI boxes, microphones, mixing consoles, and high-end sound cards.
• Broadcast and Public Address Systems — Audio signal converters, telephone couplers, and industrial audio isolators.
• Communication and Voice Equipment — Intercoms, fax machines, car radios, VoIP devices, and recording equipment.
• Consumer Audio Products — Radios, hi-fi systems, home theater equipment, and passive speaker accessories.
• Industrial, Security, and Medical — Audio splitters, noise suppressors, access control voice units, surveillance microphones, and monitoring voice channels.

Figure 5 — EE25 transformer installed at the front end of a professional microphone preamplifier.

5. Specifications

5.1 Electrical Parameters (≈ 25 °C)

Parameter	Test Condition	Value
Turns Ratio	—	1 : 4
Inductance (Red–Blue Winding)	1 kHz, 0.3 V	Typ. 900 mH (Min. 800 mH)
Inductance (Yellow–Green Winding)	1 kHz, 0.3 V	Typ. 65 mH (Min. 56 mH)
DC Resistance (DCR)	25 °C	1.55 Ω / 17.5 Ω (±10%)
Dielectric Withstanding Voltage	AC 500 V, 2 mA, 3 s	No breakdown
Insulation Resistance	500 V DC	≥ 100 MΩ
Dielectric Insulation Class	—	Class B / Class F

Inductance is measured at 1 kHz / 0.3 V; DC resistance tolerance is ±10% per product specification.

Figure 6 — Rated inductance, DC resistance, withstand isolation, and insulation resistance.

5.2 Mechanical Data

Item	Specification
Core	EE25 frame, high-grade silicon steel laminations
Dimensions (L × W × H)	26.0 × 19.0 × 14.8 mm
Terminations	Multi-color flying leads (black, white, red, yellow, green)
Lead Treatment	Pre-stripped, tin-plated copper wire ends
Winding Wire	High-purity enameled copper wire, 0.025–2.0 mm
Bobbin Material	Flame-retardant nylon, UL94V-0

All dimensions and performance parameters can be developed and customized per customer requirements.

Figure 7 — Multi-angle views, compact EE25 dimensions, and lead profiles.

Figure 8 — Close-up of windings and bobbin.

Figure 9 — Pre-stripped, tin-plated copper lead ends.

6. Quality and Testing Assurance

• Controlled Manufacturing — Every transformer is produced under an ISO 9001:2015 quality management system.
• Hi-Pot Testing — AC 500 V, 2 mA, for 3 s, with no breakdown.
• Insulation Resistance — ≥ 100 MΩ at 500 V DC.
• Flame Retardance — UL94V-0 flame-retardant bobbin and UL-certified leads.
• Regulatory Compliance — CCC, CE, RoHS, and UL.

Figure 10 — International certifications and quality compliance.

Figure 11 — Routine dielectric and insulation resistance verification for EE25 products.

Safe · Reliable · Compliant