Simply look at the JundoStream and the actual construction is less than clear. The seven ‘conductors’ are not necessarily what they seem. Instead, this is perhaps most easily understood as an exploded version of the Cat8 standard. What you see before you is, actually, four conductors with three passive spacers in between them, with each conductor representing one of those twisted pairs: but there all similarities cease. A picture is worth a thousand words – so here’s a sectional view that details the construction and materials.
Take a look at the four, separate conductor ‘pairs’ and two things are immediately obvious: firstly, each pair has gained a third, ground wire, while each conductor also has two, independent shields, together with a silk braid layer for mechanical damping. The conductors themselves are silver-plated copper, with PTFE dielectric, all of which is a step up from your standard Cat8 cable. But the really important, topological differences are to do with twist rate and shield terminations. The signal conductors are twisted to resist induced RFI, but the twist rate matters. In the standard Cat8 construction, the twist rate of each conductor has to be varied, as they are packed so close together that identical conductors would induce cross-talk. In turn, that compromises RFI rejection. By flattening out the cable construction and introducing independent shields and spacers, Reiki is able to ensure that all their conductors enjoy identical, optimum twist rate and maximum RFI rejection.
When it comes to shielding, the JundoStream adopts a single-ended drain, rather than a continuous ground connection. By terminating the shields at the send or switch end of the cable, rather than the streamer/DAC end, they prevent any noise dumped onto the network ground plane (by noisy power-supplies, processors, blinking LEDs or external pollution) from reaching the sensitive data input on your steamer or DAC, helping to keep network noise out of the audio system’s ground plane.
Of course, creating the cable itself is only half of the struggle. Having designed a cable that’s the best part of two-inches wide, fitting it into an RJ45 plug and socket is no laughing matter. You will need a pretty sophisticated junction between cable and connector, to ensure symmetrical treatment of each conductor as well as adequate strain relief. Then, you’ve got to ensure that the solution you’ve adopted actually works on a practical level. A lot of streaming DACs have closely packed socketry and you can’t afford to have one connection blocking others, while flexible tails or stand-offs risk increasing RFI vulnerability, just where the network is most sensitive.
Reiki’s solution is typically straightforward, even if the execution was extremely complex. A 3D printed ‘cowl’ was designed to mate the widely spaced conductors into the body of the industry standard, TeleGartner, metal-bodied RJ45 plug. The metal elements and connector protect the fragile junctions from outside interference, as well as providing the necessary solidity to prevent mechanical interference or failure. But – and here comes the tricky bit – in order to avoid obscuring adjacent sockets, the broad body of the cowl had to be twisted through 45 degrees, a complex operation even with the considerable aid of CAD and a 3D printer! However, the end result is pretty striking – as well as being adaptable to USB use too.
