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

1. Product Name

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

Identification. The part is marked ZXYAUDIO P3188 on the top face, with a circular pin-1 index dot. It is manufactured by Shenzhen Zhixiangyuan Electronics Co., Ltd. (ZXYAUDIO). The model, product type, package and manufacturer are stated in the product document supplied with the part.

The package is a moulded thermoplastic box rather than an open frame. The core and both windings sit inside it, the cavity is filled with black epoxy, and the metal shield is part of the assembly. That construction is what allows the part to be handled by standard SMT equipment: the body is rigid, the leads are coplanar, and there is no open winding to be damaged in the feeder or during reflow.

2. Feature

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

Integrated metal shielding. A built-in metal shield plate suppresses stray electromagnetic fields and radio-frequency interference.

Full environmental encapsulation. A thermoplastic case filled with black epoxy resin gives complete moisture, dust and vibration protection.

6-pin SMD package. Coplanar tinned solder leads, laid out 3 + 3 for high-speed automated placement and reflow.

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

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

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

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

3. Advantage

Solves ground potential mismatch. The isolation barrier separates two units that sit at different ground potentials, which is the usual cause of hum in interconnected audio gear.

Pristine transmission with zero baseline noise. Severing the electrical ground link while keeping magnetic coupling removes the noise path but leaves the signal intact.

Dual defence against radiated noise. The internal metal shield blocks interference from adjacent digital processors and switching supplies, while the epoxy body damps mechanical resonance and microphonics.

Built for automated assembly. The standardised SMD footprint replaces the hand soldering that through-hole audio transformers require, which lifts throughput and solder reliability for OEM and ODM builds.

Sealed against the environment. Potting closes the core and windings inside the case, so moisture, dust and chemical exposure do not reach them.

Tested piece by piece. Every unit is screened, not sampled, so a failed part does not reach the line.

The order of operations matters here. A transformer alone isolates, but an unshielded one still picks up radiated noise from whatever sits next to it on the board, and an open-frame one still lets moisture and flux residue reach the winding. The P3188 addresses both in one part: the shield handles what arrives through the air, the potting handles what arrives through the environment. In a mixed-signal board where a switching regulator sits a few millimetres away, that combination is the difference between a part that measures well on the bench and one that stays quiet in the enclosure.

4. Application

Professional audio equipment. Studio mixing consoles, pre-amplifiers, stage DI boxes, audio equalisers and power-amplifier input stages.

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

Broadcast and communication. Radio and television transmission gear, OB-van audio routing matrices and inter-facility audio distribution.

Commercial and automotive sound. Automotive DSP amplifiers, conference-room AV systems, PA matrix routers and teleconferencing terminals.

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

In each of these cases the transformer sits at a boundary: between a console and a stage box, between a computer and a converter, between two pieces of gear on different mains circuits. The boundary is where ground potential differs and where hum enters, and it is the point where a 1:1 isolation transformer belongs. Because the ratio is unity, the substitution does not change the gain structure of the design, which keeps the change to the bill of materials rather than to the signal chain.

5. Application Specifications

All electrical parameters and mechanical characteristics are specified at an ambient temperature of 25 C in accordance with ZXYAUDIO engineering guidelines.

5.1 Specification table

5.2 Pin configuration and terminal definition

5.3 Notes on the data in this listing

6. Quality & Testing Assurance

Every unit is tested, not sampled. Automated electrical verification screens turns ratio accuracy at 1:1 +/-2%, DC winding resistance balance and frequency-response consistency. Dielectric isolation is verified by high-voltage testing between the primary winding, the secondary winding and the shielding, so that breakdown cannot pass unnoticed.

The part is validated against standard lead-free reflow soldering thermal profiles and for high-temperature operating durability. Manufacturing runs under an ISO9001:2015 quality management system, the product is CE certified to the electrical safety directives, and materials meet the EU RoHS requirements with 100% lead-free construction.