Headphone amplifiers with optical input

Optical

— interface for digital audio transmission using TOSLINK fiber optic cable. Along with coaxial (see the relevant paragraph), it is one of the varieties of the S / P-DIF standard. Thus, the presence of this input means that the amplifier is equipped with a built-in digital-to-analogue converter and can work with a digital audio signal. At the same time, an optical cable, unlike a coaxial cable, is absolutely insensitive to electromagnetic interference. On the other hand, optical fiber requires care in handling, as it does not tolerate strong pressures and bending.

It is also worth mentioning that in some amplifiers — especially portable ones — the optical input can be built directly into the 3.5 mm jack, and to work with such an input, you need a cable that has a plug of the appropriate design. The connector itself can work in different formats — depending on the settings and the connected cable.