23 January 2016

Transformers in High-end Audio


Recent technologies and services such as smart devices and streaming have transformed the way most people consume and experience music. This has changed many attitudes toward how we listen to music and our expectations of the medium, including aspects such as fidelity and sound quality. The standard streaming and storage format MP3 and even FLAC are inferior to vinyl, but we continue to stream files, often from sites where the sound quality is further degraded. Those files are then typically listened to via headphones, smart device loudspeakers, or external speaker systems that are made with portability and utility in mind rather than sound quality.

Transformers in High-end Audio

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At the same time, however, we’re seeing a movement toward pro-audio technologies and attitudes. Vinyl and turntable sales have increased, and there has been a resurgence of high-end audio technologies and components available to audiophiles and musicians or producers alike. A growing trend toward analogue-based – that is to say, voltage-controlled – and pure analogue electronic instruments and sound systems is being seen among producers and musicians.


Valve amplifiers have remained a firm favourite among many musicians and music industry figures since their inception, but advances in digital or solid-state amplification throughout the latter half of the 20th century led to many consumers and even professionals ditching them in favour of all-digital alternatives. The return of valve amplifiers has brought with it a new industry boom for component manufacturers and power transformers.

The most common is the EI laminate transformer, although many others opt for toroidal transformers. With EI transformers, the main benefits are cost and availability. Their straight edges and shape also make them relatively easy to install.

Toroids are donut-shaped. They are often more expensive than their EI counterparts and can be harder to source, but their benefits ensure their usage in many types of high-end valve amplifiers and audio equipment. Possibly the biggest benefit is the noticeably lessened magnetic field radiation when compared to EI transformers, which is essential for that low-noise signal that professionals and audiophiles crave.

This equipment is still somewhat of a niche market, so companies such as Siga Transformers and others supplying integral valve amplifier components do most of their trade online.

There is some debate about what type of power transformer is ideal for a particular amplifier, but this often comes down to practical considerations and subjective qualities.