Today, with few exceptions, all motherboards on the market that have an integrated sound card have S / PDIF digital output. You will be able to see that when the equipment is on and if this outlet is not in use, despite the fact that most have a small hinged lid, a red light appears, and that is because your equipment is prepared to use it both at the hardware level. like software.
What is optical audio output and what does that imply?
Actually, the optical audio output is called S / PDIF (although some call it SPDIF directly) because of the S / P-DIF protocol, which corresponds to the format of digital interface Sony / Philips, and its connector is TOSLINK; In essence, instead of using copper to transmit the signal, it is literally transmitted over a fiber optic cable, and with this a fairly exact analogue is if we compare the old copper ADSL connections with the fiber optic that now serves the Internet to the most homes in the country.
Precisely, all the optical audio outputs of PC sound cards usually have a small cover that can be folded inwards when we insert the connector TOSLINK, and this is so that dust or other dirt does not get into it when it is not in use since being an optical connection, dirt or dust could hinder and even cancel the signal.
Therefore, the difference between the old minijack audio output and the optical audio output on the PC is essentially the method of connection (or communication to be more precise) and the cable that is used. Obviously, if it did not matter to use one connection than another, there would be no reason to use the optical output over the analog, right? But as you will already suppose, using the optical output has certain advantages.
As you may already suppose, a fiber optic digital interface has a lot of more bandwidth than an analog interface with copper cable, and that means that with a single digital cable we can transmit multichannel audio. In other words, with a single cable we can integrate the signal to 5.1 surround audio and formats like Dolby True Surround or DTS, while doing that in digital requires a much greater amount of wiring which, in addition, can have signal loss.
And with regard to signal loss is where we find another of its main advantages: being a digital audio output through optical fiber, either it works or it does not work but there are no “halftones”, that is, when it works it works al maximum of its possibilities always, unlike the analog signal that can suffer interference or degradation depending on environmental conditions. For all practical purposes, comparing mini Jack analog audio outputs to S / PDIF optical audio output on a PC is like going from a VGA video connection to an HDMI one.
Is it better to use digital or analog audio on the PC?
In all areas (and not only speaking of audio), digital differs from analog by continuity: in a digital system the changes are always drastic, because it goes from ones to zeros (binary system), which means that o it passes current or it does not flow, it works or it does not work, or it is white or it is black. However, the analog signal allows changes to occur in a progressive and gradual manner, maintaining continuity at all times.
Now we can think that then analog audio is better than digital because we will notice the tone changes better, but the reality is very different because this does not depend on the type of connection you have, but on how the audio has been encoded. Think that at the end of the day we are talking about connections on a PC and wherever it comes from, if the sender of the signal is the PC, it is digital and therefore the quality that we perceive later will depend on its quality.
In other words, the quality of the audio will not improve because you use a digital optical output since the quality does not depend on this but on the bitrate and others of the audio track that is reproduced; However, what you can notice using this audio output is that there will be no interference or degradation of the signal, since being digital as we have explained before either it works or it does not work, there are no half measures.
Therefore, and already answering the question of the owner: yes, it is better to use the S / PDIF optical audio output of your PC as long as your speakers or sound equipment have this input. Really, all are advantages, since although you will not gain quality you will not suffer loss of it either since there will be no interference or degradation, and you will also have the convenience of being able to centralize all the audio of the equipment with a single cable regardless of the number of speakers you have (obviously if later you have 5 speakers plus a subwoofer, these will each have their own cable but the difference is that you will not have to connect all of them to the PC, but only one of them).
Therefore, our recommendation is that whenever possible you choose the digital optical audio output over the analog mini Jack, since you will avoid problems and the connection will be much more comfortable.