AES EBU 110 Ohm Digital Cable

The very first real-time software MP3 player was a program called WinPlay3. This program was released way back in September of 1995, back in the days of half gig hard drives. As MP3s gained popularity and began to distract computer users from glorious MIDI music, Winamp from Nullsoft was released in 1997 and by the next year, Winamp in its various iterations was downloaded over 3 million times. Several years later, the first version of iTunes was released to the public in 2001. Fast forward to today, a little over a decade later, and computer audio has become very widely accepted and many audiophiles are more likely to fire up a PC than pop open a compact disc player.

The WinPlay3 Program

Because the CD player is going the way of the dodo (obsolescence), audiophiles choose to interface their PC with a DAC (digital audio converter) in order to extract the music in the best sounding way possible. A DAC requires a digital signal be carried from the PC to the external DAC. In some cases the PC has a direct output for a digital signal from the motherboard or sound card, in other cases, a user may choose to use a USB to SPDIF converter box, such as the M2tech HiFace or Musical Fidelity V-Link to name a few.

Digital signals can be carried a few different ways, either optically or via a coaxial cable. Many enthusiasts frown upon optical cables due to perceived jitter and myriad other issues, although I have found the glass ones to be acceptable in the past. Optical cables actually isolate the ground from one device to another which can be a benefit in the case of a dirty ground at the source. The other option, a coaxial cable with a single center conductor isolated with a dielectric and a return which is typically a copper mesh over the dielectric, can be terminated with either an RCA or BNC.  In the case of the AES/EBU, there is still the copper mesh over the dielectric and there are two conductors in the center.

Standard digital coaxial cables are preferred to be rated at 75 ohms, and since BNC connectors are legitimately 75 ohms, they are preferred, but in many cases BNC connectors are not offered and an RCA will suffice. If you are lucky and your PC output and DAC both have an AES/EBU jack, then you’ll have the best possible connection between your devices. AES/EBU coax cable should be rated at 110 ohms.

AES/EBU, also known as AES3, was developed by the Audio Engineering Society (AES) and the European Broadcasting Union (EBU) way before the first software MP3 player in 1985 (although revised in ’92 and ’03) and is effectively the professional version of S/PDIF. Much more additional information regarding the AES/EBU standard, including protocols, time slots and channel status bits can be found at http://en.wikiaudio.org/AES_EBU .

Musical Fidelity V-Link 192 featuring an AES EBU connection

Now that we covered what an AES/EBU is and where it came from, I’ll go ahead and assemble a nice audiophile quality one. One of the fortunate things about the AES/EBU protocol is that is calls for a standard XLR connector, of which there are many audiophile versions floating around, I’m sure some of which use time-corrected flux capacitors and pixie dust gathered during ancient times. I’ll personally be using the DHLabs Silver Sonic XLRs, which is a strange name as the contacts are gold-plated pure OFC copper (no brass!), but they’re great connectors for the dollar, and the DHLabs Silver Sonic D-110 110ohm coax cable, which has silver plated copper conductors within a PTFE dielectric, spacers for constant impedance and a 100% coverage shield.

Silver Sonic D-110 Cable and XLRs

First on the agenda is covering the wire with some nice sleeving. I selected the Techflex brand Carbon Reflex sleeving, which is a polyethylene terepthalate material braided with 3M Ultra reflective monofilament. In simple terms, the weave reflects light and looks pretty impressive.

As noted in the photo below, there are two insulated wires (positive and negative) and a drain wire which connects to the shield for the ground. Also in the center is the Silver Sonic XLR female pieces.

Sleeved with Carbon Reflex

...and here are the Silver Sonic XLR male pieces.

Silver Sonic XLR male connector

Although not necessary, I sleeved the drain wire with Teflon like the other two conductors for uniformity.

Drain wire with Teflon sleeve

These wires are soldered in place on each of the male and female connectors. The ground wire (the drain wire in this case) is soldered to pin 1, the positive wire (red in this case) is soldered to pin 2, and the negative wire (black in this case) is soldered to pin 3. Also note that with the Silver Sonic connectors, slipping the boot over the decorative sleeving requires some patience.

XLR Pin Diagram

Once everything is soldered in place, the barrels of  the DHlabs connectors are slid over the soldered connections and the three screws over each connector are replaced. The two screws over the boot in the back back a very substantial strain relief system. Below you will see the finished digital AES EBU cable. 

Finished digital AES EBU Cable

Hope you enjoyed reading this post. If you are interested in having your own custom digital AES EBU cable (or any other cable) made, please contact Zynsonix for a quote.


The Fine Print:
The above steps detailing the building of a cable are for entertainment purposes only, and not to be performed under any circumstances. The owner of this blog and all associated parties can not / will not be held responsible if you attempt the process posted and cause physical harm to yourself, your surroundings or your property. Please keep this in mind.

A Simple Recipe for a High Quality Digital Coax Cable

The audiophile world has really changed in the past decade. Most of us have moved from a stand-alone CD player to a computer-based music server. Whether you use iTunes, Foobar2000, WinAmp, MediaMonkey or some other program, you really need a quality DAC to extract your music from your PC to your audio rig. The industry has caught on and there have been myriad high-end DACs being released in recent years.

Carrying your precious 1s and 0s to your DAC should be a quality cable you can trust. A good digital cable should have an impedance of 75ohms. Cable impedance is important in digital audio because the signal runs at high frequencies. Because of this, impedance needs be matched from the source to the cable to the load. If it's not, then your end up with reflections. The concept seems to be that some of the signal is reflected back to the source along the cable. If the source isn't 75 ohms, it will return the reflection to the load, creating a time delayed reflection. I've also read some essays on the matter stating that the coax cable should be 1.5 meters (appx. 5 feet) or longer to further minimize the possibility of this effect. 

It seems that there are plenty of opinions on the above that spark long debates running thousands of pages through hundreds of threads, so that's why I'm only going to touch on it and move on ;)  The important thing for the DIYer to get out of the above is that one should use 75ohm connectors and 5 feet of 75ohm coax cable when possible (unless it's a balanced AES/EBU connector, which is a different story). 


There aren't a lot of audiophile quality DIY Coax connectors out there, so you have to spend a little bit to get the good ones. Furutech makes the FP-3-117(R) Audio grade BNC connector which is attractive and rhodium plated. There really isn't much else out at the moment that falls between this and the pro-audio quality Canare connectors. I believe Vampire used to make one but the usual suspects (PCX, Percy) don't carry it. A pair of the Furutechs will set you back approximately $40 at the time of this writing.

Furutech FP-3-117(R)

To connect these two lovely coax connectors together will be some nice quality wire. DHLabs, a company that has been around since 1992, is known for providing audiophile quality parts at reasonable prices. I'll be using the DHlabs D-75 wire, which has a solid silver-coated center conductor to maintain uniform impedance. From DHLab's website: The use of a solid center conductor minimizes signal reflections, which are very important in digital data cables. This center conductor is encased in a very uniform closed cell foam Teflon dielectric. The result of these efforts is a cable that can provide excellent performance to beyond 2 Gigahertz ... In continuing with our policy of providing maximum value, the D-75 costs much less than its performance level would suggest. I would tend to agree. I'd imagine if other companies were selling the same wire, it would be at least twice the price.

D-75 Cutaway

Using these parts together is actually fairly easy. One strips the jacket, folds back the braided shield, trims away a small amount of the dielectric, then inserts the cable into the connector. The solid core center conductor is soldered to the center pin of the Furutech, and the connector clamps down on the shield for a solderless connection. 

Example of a solderless connection

So you're thinking to yourself, "those BNC connectors look a little strange, I don't think my DAC / CD Player / etc. has those". It is actually a little less common to have nice BNC females on your gear than a generic RCA female to accept or send a digital signal, but more and more new gear seems to be including BNCs now. If one isn't already mounted on your gear but has room to mount it, one of the Vampire BNC female connectors below typically works:

Vampire BNC Female

One can either mount it free-hanging and solder wire to it or it's a drop in replacement depending on certain PCB layouts. PartsConnexion carries these, and I'm sure other retailers do as well. If one would rather not futz with it, DHLabs still makes a nice RCA plug that matches the D-75.

DH Labs RCA-3

It's certainly possible to have an RCA-3 on one side and a Furutech BNC on the other depending on the application. Here's what my completed Furutech / DHlabs coax came out like:

Furutech / DHlabs Digital Coax Cable

And here's an example of an RCA to BNC using the aforementioned DH Labs RCA-3. 

RCA to BNC Digital Coax Cable

If you'd like to have your own custom Digital Coax Cable made, please contact Zynsonix. 


I hope you enjoyed this detailed discussion of a Digital Coax cable. Please note that this post is for entertainment purposes only and not intended as a walkthrough. The owner of this blog, Blogger, and all associated parties will not be held responsible if you attempt to recreate the above cable and damage yourself or your surroundings.