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 built on a high-grade EE25 silicon-steel core and terminated with multi-color flying leads. With a 1:4 turns ratio, an inductance range of 65 mH to 900 mH at 1 kHz and pre-stripped, tinned copper lead tips, it provides impedance matching, galvanic signal isolation and ground-loop noise rejection in professional audio, broadcast, communication and industrial audio equipment.

Figure 1 — EE25 flying-lead audio isolation transformer, multi-color leads, tinned copper tips.

At a glance

Parameter	Value
Turns ratio	1 : 4
Inductance (red–blue)	900 mH typ. (800 mH min) @ 1 kHz
Inductance (yellow–green)	65 mH typ. (56 mH min) @ 1 kHz
DC resistance (DCR)	1.55 Ω / 17.5 Ω (±10%)
Hi-Pot dielectric withstand	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 for low loss, high efficiency and stable performance.
• Multi-color flying lead wires — Black, white, red, yellow and green leads are color-coded for easy identification and secure connections.
• Pre-stripped and tinned copper tips — Ready for soldering, ensuring fast and reliable installation.
• Flame-retardant nylon bobbin — High-temperature resistant UL94V-0 material for enhanced safety and durability.
• High-purity enameled copper wire — Consistent, low-distortion signal transfer from a 0.025–2.0 mm winding wire.
• Class B/F high dielectric insulation — Reliable dielectric isolation of AC 500 V between windings.
• 26.0 × 19.0 × 14.8 mm envelope — A compact body that fits dense PCB and chassis layouts.

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

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

3. Advantages

• Accurate 1:4 turns ratio — Stable inductance of 65 mH / 900 mH at 1 kHz delivers repeatable impedance matching.
• Low winding resistance — DCR of only 1.55 Ω / 17.5 Ω keeps insertion loss low and preserves signal level.
• Faithful audio transfer — Flat audio response and low harmonic distortion across the low-frequency and audio range make the EE25 suitable for high-fidelity signal paths.
• Dielectric isolation — AC 500 V, 50 Hz withstand breaks ground loops and blocks common-mode noise between equipment stages.
• Stable insulation — Insulation resistance of ≥ 100 MΩ at 500 V DC supports long-term reliability.
• Certified quality — UL-approved leads, CCC / CE / RoHS / UL compliance and ISO 9001:2015 production.

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

4. Applications

Core functions: Impedance matching · signal isolation · noise reduction (ground loop) · balanced-to-unbalanced conversion

• Professional audio and video equipment — Tube (valve) 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, vehicle radios, VoIP devices and recording equipment.
• Home audio products — Radios, hi-fi systems, home-theatre equipment and passive speaker accessories.
• Industrial, security and medical — Audio separators, noise suppressors, access-control voice units, surveillance pickups and monitor voice channels.

Figure 5 — EE25 transformer installed in a professional microphone preamplifier front-end.

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	900 mH typ. (800 mH min)
Inductance (yellow–green winding)	1 kHz, 0.3 V	65 mH typ. (56 mH min)
DC resistance (DCR)	25 °C	1.55 Ω / 17.5 Ω (±10%)
Hi-Pot dielectric withstand	AC 500 V, 2 mA, 3 s	No breakdown
Insulation resistance	500 V DC	≥ 100 MΩ
Dielectric insulation class	—	Class B / F

Measured at 1 kHz / 0.3 V for inductance; DCR tolerance ±10%, in accordance with the product specification sheet.

Figure 6 — Rated inductance, DCR, Hi-Pot isolation and insulation resistance.

5.2 Mechanical Data

Item	Specification
Core	EE25 frame, high-grade silicon steel
Overall dimensions (L × W × H)	26.0 × 19.0 × 14.8 mm
Termination	Multi-color flying leads (black, white, red, yellow, green)
Lead preparation	Pre-stripped, tinned copper tips
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 to customer requirements.

Figure 7 — Multi-angle overview, compact EE25 size and lead outlines.

Figure 8 — Winding and bobbin close-up.

Figure 9 — Pre-stripped, tinned copper lead tips.

6. Quality & Testing Assurance

• Controlled manufacturing — Every transformer is produced under an ISO 9001:2015 quality management system.
• Hi-Pot test — AC 500 V, 2 mA for 3 s, non-breakdown.
• Insulation resistance — ≥ 100 MΩ at 500 V DC.
• Flame retardancy — UL94V-0 flame-retardant bobbin and UL-approved leads.
• Compliance — CCC, CE, RoHS and UL.

Figure 10 — International certification and quality compliance.

Figure 11 — Routine dielectric and insulation-resistance verification of EE25 units.

Safe · Reliable · Compliant