 What's the best way to connect your digital audio source to your DAC or amplifier with built-in DAC? The problem is that there is now universal best solution. But that doesn't mean there isn't the best solution for your setup. In my video Why Digital Circles Influencer Sound Quality, I describe why network switches influence the sound. But the same problems play a part in all digital audio equipment and digital audio connections. Therefore it might be handy if you watch that video first. The link is in the top right corner, in the description and at the end of this video. In short, the signal over the digital connection is an analog square wave signal that can suffer from time invariance and distortion through the ground plane and other power supply problems. Both cause jitter in the signal during the digital to analog conversion. Let's look at several setups and choose the best solution in each case. In quality digital playback you want the bits in the audio file arrive at the DAC fully unaltered. All operating systems want to mix the audio with, for instance, warning beeps. Therefore the sampling frequency of the audio is changed, usually to 48 kHz. In this process the sound quality will suffer, so that should be prevented. So called BitPerfect Music Player software does this. There are many programs available. Well known ones are Audivana, Amara, BitPerfect, Decibel, J River Media Center, Pure Music, Music Player Demon, Neutral Music Player, Rune and Volumeo, but there are even more. Just google BitPerfect Music Player. When that is fixed, it's time to talk about the digital connection to the DAC. A standard modern computer will have at least USB but often also split-if or toss-link or even both. There also might be analog outputs that needs to be avoided if you go for really good sound quality. USB nowadays uses the USB Audio Class 2 standard which uses an asynchronous protocol. This sends packets of audio data to the DAC where it is buffered and sent to the digital to analog conversion circuitry against the clock in the DAC. So the clocks in the computer have no play in that. But the digital USB signal, being analog square waves, most likely is polluted by all the clock signals and the simple switch mode power supply you find in computers. That power supply will also pollute the 5 volt DC power line that every USB connection needs. See the review of the Holo Audio Titanis 800mpa for an explanation. That device sold out quickly after the review went online. It fights the aforementioned problem. Luckily there is an alternative in the Optone Audio ISO region. One step up is the Syncse Audio SU6 USB Audio Bridge that converts the USB signal to AES-EBU, split-if, toss-link and I2S. Other solutions are audiophile quality USB PCI cards that have an external power supply. And then add the audiophile grade power supply and other measures to clean up the digital output signal of a computer. To get the USB output of a computer ideal for high end audio, you could easily spend €4000 to €5000 on computer parts, including a bespoke motherboard that is clocked from the same clock as the USB card in the network card. See my review of the SOtM audiophile computer. If you use a normal home grade computer, a USB cable of say €50 might improve the sound quality. Using a heavily tweaked PC, like the SOtM or a computer sold as an audiophile grade server might benefit from high end USB cables like the network audio and audio quest cables I use in my setup 1 when a USB cable is needed. The AES-3 standard knows three variants. AES-EBU, which uses XLR connectors, 110 ohm cable and 2-7V peak-to-peak. Split-if, which uses RCA or BNC connectors, 75 ohm cable and 0.5-0.6V peak-to-peak. Toss-link, which is identical to split-if but uses an optical instead of electrical connection. AES-EBU uses slightly different subcode but the audio data structure is identical to split-if and toss-link. All three have the clock signal encoded in the data stream. If you want to know more about this, watch my video Connecting Your DAC No. 2, How Digital Can Go Run. All AES-3 formats use the source clock so the one in the computer to drive the DAC. In the DAC the receiver chip has to chase the incoming clock which will cause jitter on top of the jitter on the computer clock. Some DACs offer the possibility to switch between wide chasing and close chasing. The first position is for jittery sources, the second for low jitter signals. If you need to use one of the AES-3 connections, AES-EBU, if present on both devices, is the best. Split-if is second and toss-link to last. AES-EBU and split-if can carry signals up to 192 kHz. Toss-link officially is supported up to 96 kHz although some manufacturers support 192 kHz. In general USB will be the better option provided the receiver circuit and the clock of your DAC is of sufficient quality. Whether that is the case is easily established by comparing USB to AES-3. USB will certainly be the better choice if an active USB reclocker is used, especially if it also cleans up the USB 5-fold line or outputs quality AES-3 signals instead and your DAC can handle AES-3 properly. Basically, a network bridge is a USB, I2S or AES-3 output at a distance. It is connected to the computer of the network, which is asynchronous, like USB Audio Class 2. You need player software that can address a network bridge using protocols like DNA, UPNP, Rune, Squeezebox and so on. A good network bridge receives the digital audio over the network, cleans up the signal, buffers it and plays it out to either USB Audio Class 2, I2S or one or more AES-3 streams. Now the quality of the computer is of little relevance as long as it can handle the task of streaming audio to the network, which for a modern computer is a walk in the park. A 384 kHz 24 bit PCM file uses 18.4 Mbps. Nowadays Ethernet networks do 1000 mbps, also called 1 gigabit per second and 10 gigabits can already be found on more advanced computers. But even the gigabit network can handle many audio streams simultaneously and so does a modern computer, unless you use the computer for processor intensive tasks at the same time, like video processing or doing audio processing to DSD files during playback. Then the processor of some computers might not cope. Back to the network bridge. They come in a wide range of prices starting from a few hundred euros to tens of thousands and many streamers can be used as a network bridge too. I have two playlists on the network bridges, below 500 and above 500 euros. Links in the description below this video on YouTube. Compared to the active USB reclockers they will lead to better sound quality if your stereo is able to reproduce the difference and your ears are interested in higher quality. Network bridges generally only have one type of output, USB only Class 2, I2S or one or more AES-3 formats. But if it offers two or three interfaces, the question arises what sounds better. That again depends on the qualities of both the bridge and the DAC, so again trial and error cross your part, and mine by the way. Of course you can also use a network player. The difference with a network bridge is that it can be operated from the player itself. There can be through proprietary software, like for instance Auralic, Blue Sound and Sonos Do, but it can also be a protocol like DLNA or Squeezebox, in which case a DLNA or Logitech Media Server program has to run on a computer or NAS. Network players might need an external DAC or can have a DAC built in. In the first case, again it's the implementation that defines what cable sounds the best. In my setup 2A I use USB between the LOUS bridge signature, the network bridge and the Denofrips Aries 2 DAC. But in my setup 1A I use AES-EVU between the Grim Audio Mu1 digital player and the Core Dave DAC. I know some of you want simple answers. This might be found on other places on Dubeb. Remember that with one watch you know the time, with two watches you're never sure. Trust your ears, young viewer, ears you trust. Which brings us to the end of this program. See you next week, Friday 5pm, Central European time. If you don't want to miss that, subscribe to this channel or follow me on the social media, so you will be informed when new videos are out. Let me reach even more people by giving this video a thumb up or link to this video on the social media. It is much appreciated. Many thanks to those viewers that support this channel financially, especially in these times. It keeps me independent and lets me improve the channel further. If that makes you feel like supporting my work too, the links are in the comments below this video on YouTube. I am Hans Beekhuyzen, thank you for watching and see you in the next show or on the DHBproject.com. And whatever you do, enjoy the music.