As we known, audio transformer is strict with handling noise, but recently, many people raise questions on the forum about: they have no idea why audio transform produce noise when operating on load. Today we will take this problem as a subject to simply explain why it happens and how to deal with it.
As professors in this field suggest that transformers will produce sound on its operating process, the same with audio transformers. Because the silicon steel sheet in the iron core will change under the action of the alternating magnetic field, that is magnetostriction, it will cause the iron core to periodically vibrate with the excitation frequency to generate noise. In normal circumstances, the audio transformer will also emit a subtle sound when it is running, but this sound is continuous and can hardly heard , so it cause little effect to the acoustic fidelity of amplifier.
One aspect of excessive noise may due to the quality problems of the audio transformeritself:
(1) The manufacturing process of the audio transformer is not standardized, and the enameled wire is not evenly and tightly wrapped around the transformer core during winding.
(2) There is a problem with the quality of the core of the audio transformer. The core is inferior, for example, the thickness of the silicon steel sheet is uneven, and it is not pressed tightly during rolling,it’s easy to loose when working.
The other aspect of excessive noise attribute to external factors :
(1) Loose assembly of coil and iron core.
(2) The installation base plate of the audio transformer is too thin and the strength is poor.
(3) The audio transformer is overloaded, the temperature rise is too high, and there is thermal noise.
(4) There is an overvoltage in the power grid. Generally speaking, the single-phase grounding or electromagnetic resonance of the power grid will cause overvoltage, and the resulting sound will be louder than usual.
Therefore, if the audio transformer you buy excludes external factors, the noise is still very large, you must consider whether you purchase a inferior-quality transformer ,choosing a good transformer with guaranteed quality is an effective way to reduce noise.
ECKO Audio Transformer's selection of iron core material and production process requirements are very strict. The material is selected from high-quality cold-rolled silicon steel sheet seamlessly wound iron core, which is wound with pure copper wire, the process is smooth, and Epoxy resin is poured into the middle hole of the audio transformer, which effectively reduces the noise generated during the operation of the transformer. In addition, ECKO audio transformer also has the characteristics of no interference, less magnetic leakage, small leakage inductance, high coupling coefficient, wide frequency pass, and low signal distortion.