QED Reference Ethernet Cable

QED Reference Ethernet Cable

 

This high-performance cable has been specifically designed to deliver the best possible audio quality for high-resolution digital music. With the ability to support up to 32 bit/384 kHz or DSD512 quality, this cable is ideal for audiophiles who demand the highest level of sound quality from their audio equipment.

The cable complies with the Class I Category 8.1 standard, ensuring that it can handle even the most demanding applications. It supports 40G Ethernet, providing a fast and reliable connection for streaming high-quality audio content.

To ensure the best possible sound quality, the cable features ferrite insulation, low-loss dielectric, and gold-plated Telegärtner plugs. These components work together to deliver ultra-low jitter, resulting in a clean and clear sound that is true to the original recording.

The cable also features 99.999% OFC, 24 AWG conductors with customized twist rates to reduce inter-pair cross-talk. This further improves the audio signal quality, ensuring that every detail of the music is faithfully reproduced.

Finally, the cable features a stylish White Pearl finish that will complement any high-end audio system. With its superior performance and design, this cable is the perfect choice for those who demand the best possible sound quality from their high-resolution digital music.

 

What QED Say

QED introduces its new Reference Ethernet cable, providing the most accurate and stable connection between your high-resolution digital audio streamer and local network. Unlike most CAT5e's that only have an 150MHz bandwidth, the Reference Ethernet is a Class I Category 8.1 patch cable with a bandwidth of 2000 MHz, the ability to support 40G Ethernet and can accomodate 32bit/384 kHz hi-res PCM streams, having the headroom to cope with even the most data-intensive applications.

QED have been designing and engineering superior analogue and digital cables for more than 45 years and using this knowledge they have been able to produce the Reference Ethernet that avoids timing errors from cross-talk between cable pairs, ensures there is enough bandwidth for Hi Res data rates all while minimising insertion losses usually caused by poor contact quality and impedance matching.

 

Features

• Specifically designed for high-resolution audio up to 32 bit/384 kHz or DSD512 quality
• Complies with Class I Category 8.1 standard
• Supports 40G Ethernet
• Ferrite insulation, low-loss dielectric and gold-plated Telegärtner plugs combine to deliver ultra-low jitter
• 99.999% OFC, 24 AWG conductors with customised twist rates for lower inter-pair cross-talk
• Stylish White Pearl finish

 

Design

By twisting the 24AWG 99.999% OFC copper conductors together, the cables swap between which is nearest to the noise signal once per twist. In this way the noise signal becomes the same in each conductor - common mode rejection reaches nearly 100% and the noise is eliminated. The four twisted pairs have different twist rates which cut down on cross talk between pairs and contrivutes to ultra-low jitter performance. Low jitter or timing error performance of the cable is the main parameter which allows it to operate at speeds up to 40 Gb/s. Each pair has a Myler wrap around it to help maintain the 100 Ohm impedance, required by the CAT 8 standard. Unique to QED, a ferrite impregnated inner jacket shields the high bit-rate signals from external high frequency noise which can contribute to loss of signal bandwidth. To maintain low insertion loss, the Reference Ethernet has gold-plated Telegärtner plugs with 360 degree shielded die-cast bodies and high torque cable glands. Finally, the cable is finished in pearl white PVC to complement hi-end audio products.

 

Twisted Pairs

Ethernet uses differential signalling to counteract outside interference. The receiving equipment measures the difference signal between the two wires and rejects any component of the signal that is equal but not opposite (i.e. common mode). Any noise signals electrically or magnetically coupled to the data signal affect each conductor equally thus they arrive at the receiver in common mode and are rejected. However, if the noise signal is in close proximity to the signal cables it is inevitable that one of the conductors will lie closer to the noise source than the other so that the induced noise signal is not the same for each conductor. In this instance the common mode rejection is not perfect and some of the noise is transmitted to the receiving equipment. By twisting the conductors together the cables swap between which is nearest to the noise signal once per twist. In this way the noise signal becomes the same in each conductor – common mode rejection reaches nearly 100% and the noise is eliminated.

If more than one twisted pair is present in a single data bundle (such as in ethernet cabling) then the conductors of adjacent pairs become a source of noise and can lie alongside each other for some distance partially undoing the effect of common mode rejection afforded by the twisting of the conductors. Therefore, in Reference Ethernet cables we specify that the twist rate or pitch of the conductor pairs should be dissimilar to counteract this spoiling effect and reinforce the inherent common mode rejection characteristics of the differential signalling system.

Insertion Loss

Insertion loss refers to the loss of signal strength at the far end of a line compared to the signal that was introduced into the line. This loss is due to the electrical impedance of the copper cable, the loss of energy through the cable insulation and the impedance caused by the connectors. Insertion loss is usually expressed in decibels dB with a minus sign. Insertion loss increases with distance and frequency. For every 3 dB of loss, the original signal will be half the original power. Due to its accurate characteristic impedance, Reference Ethernet exceeds the requirement for CAT 8 insertion loss by up to 20 dB.

 

TDR (Time Domain Reflectometer)

Any impedance mismatch between the cable and the source or sink will cause the signal to be reflected back and forth – this is known as return loss. In the graph below, the reflected signal is shown by the peaks at the near end and far end of the correctly terminated cable. Ideally, no peaks would be seen, showing that all of the energy has been delivered to the load. In practice it is very difficult to get higher than 90% of the signal delivered to the load, which is why a very small reflection can still be seen in the graph.

Reference Ethernet TDR Fluke DSX 8000 CAT 8 Cable Analyzer

 

Even so, due to its precision-engineered Telegärtner plugs, Reference Ethernet exceeds the returns loss demanded by CAT 8 by 3.2 dB. Attenuation-to-Crosstalk ratio (ACR) indicates how much stronger the attenuated signal is than the crosstalk at the destination. Reference Ethernet exhibits an ACR figure up to 25 dB better then the requirement of the CAT 8 standard.

 

Reference Ethernet Return Loss Fluke DSX 8000 CAT 8 Cable Analyzer

 

Specification

• Outside Diameter: 9 mm
• Colour: White Pearl
• Plugs: Telegärtner Profinet CAT 8
• Construction: F/FTP
• Conductor size: 24 AWG
• Characteristic Impedance: 100 ohm
• Patch Cable Category: Class I CAT 8.1
• Maximum Bandwidth 2000 MHz
• Maximum bit-rate: 40 Gb/s

 

Transmission Characteristics CAT 8 Test Pass Margins*:

• Insertion Loss 20 dB
• Return Loss 3.2 dB
• NEXT 11.3 dB
• ACR-F 8.3 dB

*Indicates at least how much better than the CAT 8 standard the cable measured.

 

About QED Cables 

QED is an award-winning British company with over 40 years of experience in the audio-visual connectivity industry.

In 1973 Bob Abraham and Ian Vine founded QED Audio Products and changed the way people think about hi-fi cables. By the time QED 79 strand speaker cable was launched in 1978, it wasn’t looked upon as ‘just another speaker cable’ but was instead regarded as a serious hi-fi component, making a fundamental change in the way people thought about cables.

QED's reputation for innovation and technical excellence is known throughout the world. The latest computer-aided design techniques allow their research and development team to keep pace with technological advances and deliver products that achieve the highest levels of performance and reliability. This is why QED products are recommended by so many of the world’s leading hi-fi and home theatre equipment manufacturers.

QED offers a range of connectivity products from consumer and installation cables, wireless products and switching devices to satisfy every audio visual need.

QED is Europe's number one award-winning connectivity brand and has won more prestigious cable awards from ‘What Hi-Fi? Sound & Vision’ magazine than any other brand (Awards 1981–2013).