Similar to power transformers in terms of construction but typically much smaller in size, audio transformers — also called audio frequency (AF) transformers — perform an array of critical functions in amplifier circuits spanning the audio band of frequencies that the human ear can detect, typically from 20 Hz to 20 kHz.
Impedance matching is one of the most important functions. For example, a basic vocal amplification setup will include a microphone, cables, and an amplifier input, each of which may have different impedances that can result in signal loss. Using an audio transformer for impedance matching will prevent signal reduction due to impedance mismatching.
Taking this setup one step further, the signal can then go from an amplifier to a loudspeaker. Speakers have low input impedance, while amplifiers have much higher output impedance. Matching them up with an audio transformer facilitates the transfer of maximum power from the amplifier to the loudspeaker. This is how these devices get their name: Audio transformers “transform” the impedance of input and output circuits by raising low impedance or reducing high impedance as needed in order to transfer the maximum amount of AC power between circuits and devices.
Since transformers have the ability to “transform,” or change, the apparent impedance of a circuit input or output, they may be used in several applications that require transfer of the maximum amount of AC power between circuits. Transformers can make a low impedance appear much higher, or a high impedance much lower.
And in audio setups that involve amplifiers and loudspeakers, audio transformers play an important role, ensuring that the AC audio signal reaches the loudspeaker without adverse effects from the amplifier’s DC that can interfere with loudspeaker operation.
These transformers also exhibit great isolation properties. Because there is no direct connection between the primary and secondary windings inside them, audio frequency transformers can provide complete electrical isolation between input and output circuits, such as those between amplifiers and loudspeakers, which helps to improve safety.
Audio transformers are also capable of performing several of these functions simultaneously.
Audio Transformers from Triad Magnetics
Customers can expect reliable, efficient performance when working with audio transformers engineered and manufactured by Triad Magnetics. Since 2005, all of our standard audio transformers have met the requirements of 2015/863/EU, the RoHS initiative.
Triad Magnetics’ U.S. Design Center located in Perris, California, provides extensive custom design services with rapid design, prototyping, and testing – all backed by ISO 9001:2015 certification. With over 50 years of experience, our engineers also have the capability to modify our existing standard products to make sure you get the right audio transformer for your project.
Our 40+ standard audio transformer products fall into the following three categories:
Mil-T-27E Red Spec Printed Circuit Audio Transformers – These high-reliability audio transformers provide both the durability and precision required for demanding jobs. This line of Red Spec audio transformers is ideal for a wide variety of applications. Designed and constructed to meet the stringent requirements of MIL-T-27E, these transformers feature precision-spaced plug-in terminals to provide fixed mounting centers, an epoxy-molded case with a .020” recess for ease of solder inspection, and gold-plated leads made of high-strength nickel alloy that are .020” in diameter. Red Spec audio transformers ensure optimal performance from 300 Hz to 100 kHz.
PC Mount – Plug-In Printed Circuit Audio Transformers – These audio transformers are well-suited to numerous jobs in the audio industry, including line matching, telephone coupling, pulse trigger, interstage, output, isolation, and input applications. These models feature a bobbin with plug-in terminals spaced to provide fixed mounting centers, as well as pins that are a rugged .042” square, minimizing the occurrence of bent pins caused by handling.
Data/Voice Coupling Transformers – Triad telecommunications audio transformers are designed to meet the requirements for access over leased private lines or through the dial-up switched telephone network. The TY series of audio transformers is used in a variety of applications, such as impedance matching, isolation, repeat coil, line balancing, bridging, and hybrid circuits. These transformers are designed to comply with Part 68 of the FCC’s rules regarding the direct connection of terminal equipment (TE) to the public switched telephone network (PSTN) and the wireline carrier-owned facilities used to provide private line services.
Curious to learn more? Browse our online catalog of audio transformers to see how our products can help with your specific application needs, or reach out to our team to learn more about our custom audio transformer capabilities.