Optical audio cables: types, selection and application

Most of the cables used are designed so that electricity is an integral part of communication between devices. Both digital and analog streams imply an electrical impulse transition. But the optical output is a completely different signal transmission scheme.

An optical audio cable is a fiber made from quartz glass or a special polymer.

The difference between these two products is that polymer fiber:

• resistant to mechanical stress;
• has a small price tag.

Optical fiber made from silica glass has the best performance but is expensive. Moreover, such a product is fragile and easily disintegrates even from slight mechanical stress.

Despite all of the above, optical output is always beneficial. Of the advantages, it can be noted:

• electrical noise does not affect signal quality in any way;
• there is no own electromagnetic radiation;
• a galvanic connection is created between the devices.

To get high quality sound, you will need to follow a few rules:

• the length of the used optical cable cannot exceed 10 meters - it is better if up to 5 meters;
• the thicker the cable used, the longer its service life;
• it is better to use a product that has an additional nylon shell in the design;
• the cable core must be glass or silica, since they are much superior in their characteristics to plastic models;
• pay special attention to the technical characteristics of the optical fiber, its bandwidth should be at the level of 9-11 MHz.

The cable length of 5 meters was chosen for a reason. This is exactly the indicator at which the transmission quality remains high. There are also thirty-meter products on sale, where the signal quality does not suffer, but in this case everything will depend on the receiving side.

When audio is transmitted over an optical channel, it is first converted to a digital signal. The LED or solid state laser is then sent to a photodetector.

All fiber optic conductors can be divided into two large groups:

• single-mode;
• multimode.

LEDs act as a light emitter in the design of such optics. They represent a short-lived and, accordingly, inexpensive device. In this particular case, the cable length should not be more than 5 meters.

The diameter of such a fiber is 62.5 microns. The shell is 125 microns thick.

It should be understood that such products have their own advantages, otherwise they would not be used. The low price made it especially popular in the modern world.

In the single-mode version, the beams are directed in a straight line, which is why the distortion is minimal.The diameter of such a fiber is 1.3 microns, the wavelength is the same. Unlike the first option, such a conductor can be more than 5 meters long, and this will not affect the sound quality in any way.

Optical audio cables are often used for speakers and other sound reproduction systems. Before buying a product, you should pay attention to the following points:

• although it is desirable for the cable to be short, its length should be reasonable;
• it is better to opt for a glass product so that there are a lot of fibers in the design;
• the fiber should be as thick as possible, with an additional protective sheath that can protect against negative mechanical stress;
• it is desirable that the bandwidth be at the level of 11 Hz, but it is permissible to reduce this indicator to 9 Hz, but not lower;
• upon detailed examination, there should be no signs of kinks on the connector;
• it is better to buy such products in specialized stores.

In the case when there are only a couple of meters between devices, it makes no sense to purchase a cable 10 meters long. The higher this indicator, the greater the likelihood of distortion of the transmitted signal.

Do not think that a high price is not an indicator of quality. Quite the opposite: when purchasing cheap products, you need to prepare for the fact that the adapter will greatly distort the sound... Or it may be that it will not exist at all.

It must be connected to the Toslink port.

To connect an optical audio cable, you will need to perform the following procedure:

• to throw the fiber of the required length;
• find the corresponding ports on the devices;
• turn on the devices.

The connection port can also be called:

• Optical Audio;
• Optical Digital Audio Out;
• SPDIF.

The cable slides into the connector easily - you just need to push it. Sometimes the port is covered by a lid.

The audio signal begins to flow as soon as both devices are turned on. When this does not happen, it is required to check the activity of the audio output. This can be done through the "Settings" option.

For details on choosing a cable, see below.