Based on what we've been told thus far, two questions arise. One, if exotic 'audiophile' Ethernet wires make an audible improvement as reviewers and users report, could this be due to incorporating an actual isolation transformer perhaps in the receive-end connector; or do they duplicate its noise-suppressing function by some other means? Two, does the recommendation of placing this passive device close to the receive and not send end imply a certain amount of insertion loss? The first question remains open-ended. I asked May Park about the second. Then I issued the obvious third. Besides an isolation transformer, what else was in the box when their materials talk of 'sound tuning'? I fully expected a diplomatic soft pedal. IP deserves protection. But that never stops our sort. Diplomacy ain't our thing. May proved unfazed. "Our device contains 10GBASE-T Ethernet magnetics. And yes, it does cause some insertion loss. That's why a short distance to the PC is highly recommended." By another name, her explanation mentioned the isolation transformer again. I rephrased my question on what else. With her in a different time zone, I had the answer the next day.

On Merging's pro-audio Hapi DAC, there's no USB anywhere but two Ethernet ports, BNC word-clock i/o and multi-pin parallel ports.

But first, from the website, "...several standards-based options exist for 10G Ethernet. They range from single-mode fiber to twin-ax cable. Of all available options, 10GBase-T aka IEEE 802.3an is arguably the most flexible, economical, backwards compatible and user-friendly. It was designed to operate with the familiar unshielded twisted-pair cable technology already pervasive for 1G Ethernet to interoperate directly with it. With a single cable type, 10GBase-T is capable of covering any distance up to 100m and reach 99% of the distance requirements in data centres and enterprise environments...10GBase-T is the 4th generation of so-called Base-T technologies. They all use RJ45 connectors and unshielded twisted-pair cabling to provide from 10Mbps to 10Gbps data transmission whilst being backward compatible with prior generations...The 10GBase-T transceiver uses full duplex transmission with echo cancellation on each of the four twisted pairs available in standard Ethernet cables. This transmits an effective 2.5Gbps per pair. These bits are transformed into a bandwidth-reducing line code called 128-DSQ for double square. This limits analog bandwidth utilization of a 10GBase-T modem to 400MHz."

At £1'889/3m, AudioQuest's Diamond Ethernet cable has the voodoo police write rip-off tickets.
If you read this paper fully, you'll see many potential ops for interference and noise in Ethernet hardware. From this one assumes several layers of performance which aren't about transmission failure but degrees of noise. This segues right back to the sole purpose of the SOtM box: to reduce/eliminate noise which rides the pipeline between your Internet router and music computer. At home, it's the default connection for wired streaming. But not just there.

As I was told during my visit with Swiss pro-audio experts Merging Technologies of Pyramix fame, in recording and mastering studios with their long distances, multi-channel bandwidth needs and multiple digital devices sync'd to the same master clock, Ethernet has been the default transmission protocol for years already. Hence Merging's upcoming consumer model migrates it to home use with an Ethernet port. No longer beholden to the 5m USB limit, one can now store one's music computer in another room or on a different floor altogether and exploit Ethernet's potential 100m reach (if likely not with Diamond-priced wiring).

"Re: 10GBASE-T Ethernet Magnetics vs. an Ethernet isolation transformer, they'd indeed be similar but don't serve the exact same purpose. The iSO-CAT6 is tuned with a special circuit we developed so it exceeds products which simply use an isolation transformer. Our engineer Mr. Lee will get you a more detailed answer." Sean Lee did indeed contact me a few minutes later from his private gmail account. "The 10GBASE-T Ethernet Magnetics is an Ethernet isolation transformer but the only one which supports the 10GBASE-T specs. Those are of much higher bandwidth/speed and less loss/noise than 10/100BASE-T, hence suitable for a far higher-quality LAN connection. Most isolation transformers can’t support Gigabit Ethernet. We use a CAT6-compliant RJ45 connector so the iSO-CAT6 fully supports the CAT6 connection. As you know, CAT6 or CAT7 are more suitable for a network audio configuration. (I can’t find any information about whether competing LAN isolators support 10/100BASE-TX, Gigabit Ethernet or 10G Ethernet.) About the special tuning circuit, we designed a passive network consisting of passive electronic parts which don't influence the LAN signal but do affect noise. This doesn’t degrade the LAN signal quality but much improves the sound." The thinking reader will immediately realize that the actual quality of their LAN transmission is set/limited by the specific Internet router in use; the current load on it; and the speed and bandwidth a plan with a given IT provider pays for.

As Sean Lee put it, "if a network router is not hi-speed compliant like 1000BASE-T, the network connection will operate at the lower speed (10/100BASE-TX). But if a customer uses CAT6 or CAT7 cable with a 10/100BASE-TX router, one generally still gets better sound than using a CAT5 cable. That is why a high-speed network connection/cable is/are needed in network audio." About their CAT6 S-FTP Ethernet cable, May wrote that "its electrical characteristics are similar to other brands but we apply special shielding for better performance. It simply cannot be compared to a Belden CAT6 [incidentally, Belden CAT6a is exactly what we have - Ed]."

Relative to similar isolator solutions in the hifi sector, Acoustic Revive have their RLI-1 LAN isolator ($229), Acousensce from Germany their Giso ($331 - $464 depending on version). TotalDAC build a filter into their 2m Ethernet cable (€390).