ZXYAUDIO P3188 1:1 Audio Isolation Transformer - 6-Pin SMD, Integrated Metal Shield, Epoxy Encapsulated | Eliminates Ground Loop Hum, Suppresses EMI/RFI, -40 to +85℃

1. Product Name

ZXYAUDIO P3188, 1:1 audio isolation transformer, 6-pin SMD package, fully sealed with integrated metal shield. Turns ratio 1:1 ±2%, operating temperature -40°C to +85°C, compliant with CE / RoHS / ISO9001:2015 standards.

Marking. The top surface is printed with ZXYAUDIO P3188 and features a circular pin-1 index dot. This product is manufactured by Shenzhen ZhiXiangYuan Electronics Co., Ltd. (ZXYAUDIO). Model, product type, package, and manufacturer are noted in the accompanying product documentation.

The package is a molded thermoplastic case rather than an open-frame construction. The core and both windings are housed inside, the cavity is filled with black epoxy, and the metal shield is an integral part of the assembly. This construction allows the device to be handled by standard SMT equipment: the body is rigid, the pins are coplanar, and no exposed windings can be damaged during feeder or reflow processing.

2. Product Features

1:1 turns ratio (primary : secondary). Unity-gain signal coupling with no level attenuation, achieving precise impedance matching across the entire audible spectrum.

Integrated metal shield. Built-in metal shield plate suppresses stray electromagnetic fields and radio frequency interference.

Fully sealed environmental protection. Thermoplastic housing filled with black epoxy provides comprehensive protection against moisture, dust, and vibration.

6-pin SMD package. Coplanar tinned solder pins in a 3+3 arrangement, suitable for high-speed automated placement and reflow soldering.

Ground loop hum elimination. Breaks the galvanic ground connection, eliminating 50/60 Hz hum, buzz, and common-mode interference.

High signal integrity. Low total harmonic distortion, flat frequency response, and precise phase linearity.

Wide temperature stability. Rated operating temperature -40°C to +85°C, covering industrial application conditions.

Global standards compliance. 100% lead-free, RoHS compliant, and CE certified, meeting international electronic equipment safety requirements.

3. Product Advantages

Resolves ground potential mismatch. The isolation barrier separates two devices at different ground potentials, a common cause of hum in interconnected audio equipment.

Clean transmission with zero noise floor. Breaking the electrical ground loop while maintaining magnetic coupling eliminates the noise path while preserving the complete signal.

Dual protection against radiated noise. The internal metal shield blocks interference from adjacent digital processors and switching power supplies, while the epoxy body suppresses mechanical resonance and microphonic effects.

Designed for automated assembly. The standardized SMD pad layout replaces the manual soldering required for through-hole audio transformers, improving throughput and solder reliability for OEM and ODM production.

Environmental sealing protection. Encapsulation encloses the core and windings within the housing, preventing moisture, dust, and chemicals from penetrating.

Unit-by-unit testing. Every unit undergoes 100% inspection rather than sampling, ensuring defective products never reach the production line.

Operational sequence matters here. A bare transformer can achieve isolation, but an unshielded transformer will still pick up noise radiated by adjacent components on the PCB, while an open-frame transformer allows moisture and flux residue to reach the windings. The P3188 solves both problems in a single device: the shield handles airborne interference, and the encapsulation handles environmental intrusion. On a mixed-signal board where a switching regulator sits mere millimeters away, this combination determines whether the device measures excellently on the test bench or remains quiet inside the chassis.

4. Applications

Professional audio equipment. Recording studio consoles, preamplifiers, stage direct injection boxes, audio equalizers, and power amplifier input stages.

Audio interfaces and DACs. USB audio sound cards, analog-to-digital converters, studio recording interfaces, and digital signal processors.

Broadcast and communications. Broadcast and television transmission equipment, OB van audio routing matrices, and inter-facility audio distribution systems.

Commercial and automotive audio. Automotive DSP amplifiers, conference room AV systems, public address matrix routers, and teleconferencing terminals.

Industrial and test instrumentation. Ground-isolated audio measurement systems, telemetry equipment, and industrial intercom systems.

In each of the above applications, the transformer sits at a boundary: between the console and the stage box, between the computer and the converter, between two devices on different mains circuits. This boundary is exactly where ground potential differences and hum enter, and it is where the 1:1 isolation transformer does its job. Since the turns ratio is 1:1, replacement does not alter the design’s gain structure, so only the bill of materials needs to change without touching the signal chain.

5. Application Specifications

All electrical parameters and mechanical characteristics are specified at 25°C ambient temperature per the ZXYAUDIO engineering guidelines.

5.1 Specification Table

5.2 Pin Configuration and Terminal Definitions

5.3 Notes on the Data in This Listing