40VA EI Transformer for Audio Amplifiers

Designed for Reliable Audio Power Applications

1. Stable Voltage Output

The transformer is designed to provide stable secondary voltage under the specified operating conditions. The winding design can be optimized according to the required input range, output voltage and load characteristics.

2. Copper Windings

Copper windings provide reliable electrical conductivity and support consistent long-term performance. Wire diameter and winding construction are selected according to the rated power, current and allowable temperature rise.

3. Low-Noise Design

The EI core assembly, winding arrangement and mechanical clamping can be optimized to reduce vibration and operating hum. This makes the transformer suitable for audio amplifiers and other noise-sensitive electronic equipment.

4. Secure Clamp-Mounted Construction

The metal mounting clamp holds the laminated core firmly and provides a convenient installation method. Clamp dimensions and mounting-hole positions can be adapted to the customer’s enclosure.

5. Application-Specific Engineering

The transformer can be designed around the customer’s actual operating voltage, load current, duty cycle, installation space and temperature-rise requirements—not only nominal voltage and power.

6. Flexible Protection Options

Thermal fuses, electrostatic shields, insulation systems and other protection options can be incorporated according to the application and applicable safety requirements.

Customization Options

Custom-Built to Match Your Equipment

Primary and Secondary Voltage

Single or multiple primary and secondary windings can be designed for different input and output voltage requirements.

Rated Power

Rated power can be adjusted according to the equipment load, operating time, installation conditions and allowable temperature rise.

Transformer Dimensions

Core size, overall height and installation dimensions can be customized to fit the available space inside your equipment.

Lead Wire Length and Color

Lead wire length, wire gauge, insulation type and color coding can be produced according to your wiring diagram.

Terminals and Connectors

Available connection options include flying leads, solder terminals, terminal blocks and customer-specified connectors.

Electrostatic Shield

An electrostatic shield can be added between the primary and secondary windings to help reduce capacitive noise coupling.

Thermal Fuse

Internal thermal fuses or thermal protectors can be incorporated according to the required operating temperature and protection design.

Mounting Hardware

Metal clamps, mounting plates, screws, insulating pads and other installation accessories can be supplied where required.

Application Scenarios

Professional Audio Amplifiers

Provides isolated AC power for amplifier power-supply circuits where dependable voltage conversion and mechanical durability are required.

Hi-Fi Audio Systems

Suitable for integrated amplifiers, power amplifiers and other Hi-Fi equipment requiring a customized low-voltage AC supply.

Pre-Amplifiers

Can be designed for low-power audio signal equipment with application-specific voltage, shielding and noise-control requirements.

Studio Equipment

Used in studio electronics, audio processors and other equipment requiring stable transformer-based power conversion.

Power Conditioning Equipment

Suitable for voltage conversion, isolation and power-distribution functions in selected power-conditioning systems.

Industrial Electronic Equipment

Can be customized for control systems, test equipment, instrumentation and other industrial electronic applications.

Why Choose ECKO?

Engineering and Manufacturing Support from Prototype to Production.

Transformer Manufacturing Experience Since 2000

ECKO has manufactured customized transformers and wound components for industrial and commercial applications since 2000.

Engineering Design Support

Our engineering team evaluates electrical specifications, installation restrictions, insulation requirements and operating conditions before production.

Prototype Production

Prototype transformers can be produced for electrical, mechanical and application testing before mass production.

100% Electrical Testing

Production units undergo specified electrical tests before shipment to verify conformity with approved requirements.

Custom Low-Volume Production

We support customized transformer projects with flexible production quantities, subject to product design and material requirements.

Material Traceability

Key production materials can be managed through documented purchasing, incoming inspection and production records.

Drawing and Sample Approval

Mechanical drawings, electrical specifications and prototype samples can be submitted for approval before mass production.

Production and Test Documentation

Inspection records, test reports and other technical documents can be provided according to the project requirements.

Quality Testing

Electrical and Mechanical Verification

Each transformer is inspected according to its approved technical specification and quality-control requirements.

Test voltage, duration, acceptance limits and test conditions are determined by the approved specification and applicable project requirements.

Customization Process

From Your Requirements to Mass Production

1. Submit Requirements

Provide the input voltage, output voltage, rated current or power, frequency, dimensions, application and required approvals.

2. Engineering Evaluation

Our engineers evaluate electrical feasibility, core selection, winding structure, insulation system, temperature rise and mounting requirements.

3. Quotation and Drawing

We provide a commercial quotation and, where applicable, a technical drawing or specification sheet for confirmation.

4. Prototype Production

Prototype units are manufactured according to the confirmed electrical and mechanical requirements.

5. Sample Approval

The customer tests the samples and confirms the electrical performance, dimensions and installation compatibility.

6. Mass Production

Production begins according to the approved sample, drawing, bill of materials and quality requirements.

7. Final Inspection

Finished transformers undergo the required inspections and electrical tests before packing and shipment.

Product FAQ

Frequently Asked Questions

1. What is an EI transformer?

An EI transformer uses an EI-shaped laminated steel core secured by a metal mounting clamp. The clamp keeps the core assembly firmly in place and provides convenient mounting points for installation inside audio or industrial electronic equipment.

2. Is this 40VA EI transformer suitable for an audio amplifier?

It can be designed for professional audio amplifiers, Hi-Fi systems and related audio equipment. The final design should be based on the amplifier’s required secondary voltage, load current, peak power demand and operating duty cycle.

3. Can the 220–240V input be changed?

Primary voltages such as 100V, 110V, 115V, 120V, 220V, 230V and 240V can be evaluated. Dual-primary configurations, such as 115V/230V, may also be available.

4. Can you customize the 12V output?

The secondary voltage can be customized. We can also evaluate centre-tapped outputs, dual outputs and multiple independent secondary windings.

5. Is 40VA the input power or output capacity?

The 400VA rating represents the transformer’s apparent power capacity under specified operating and thermal conditions. The available output current depends on the required secondary voltage and transformer design.

For example, a theoretical 12V output at 400VA corresponds to approximately 33.3A. The final current rating must be confirmed according to voltage regulation, temperature rise and operating conditions.

6. Can you provide a 12-0-12V centre-tapped output?

Centre-tapped windings such as 12-0-12V can be designed. Please specify whether the required rating applies to the complete winding or to each half of the winding.

7. How do you reduce transformer hum?

Transformer hum can be influenced by core material, flux density, lamination assembly, winding construction, clamping pressure, mounting method and the quality of the input waveform. We optimize these factors according to the application, although actual system noise also depends on equipment installation and mains conditions.

Need a Custom EI Transformer for Your Audio Equipment?

Send us your input voltage, output voltage, rated power, available dimensions and mounting requirements. ECKO’s engineering team will evaluate your application and recommend a suitable transformer design.