
Network audiophiles have been using fiber media converters for years. Companies like TP-Link offer a number of options in the $20/each price range that do the job just fine. But, what’s the job?
Simple — a fiber media converter takes an Ethernet input and converts it to a fiber optic output, thus eliminating the possibility of electrical noise getting into your hifi via an Ethernet cable. In most cases, you need a pair because there aren’t many hifi devices that offer fiber input. With a pair of TP-Links, you get Ethernet In > Fiber Out > Fiber cable > Fiber In > Ethernet Out. Electrical noise free.
One has to wonder how this kind of device, a fiber media converter, can be improved upon. After all, using fiber to galvanically isolate the noisy network side from the susceptible analog/hifi side is accomplished by inserting that fiber link. What more is needed?
Enter ADOT (Audiophile Digital Optical Technology), a new company with a direct connection to Melco Syncrets in Japan. Melco makes a number of well regarded music servers as well as an audiophile Ethernet switch (Melco S100Audiophile Dataswitch), and Ethernet cables.
ADOT recently released a number of Media Converters, purported to improve on the basic TP-Link kind of device.
From the press release:
ADOT’s technology optimises the functionality of audio over fibre. The company’s plug ‘n’ play optical fibre upgrade kits introduce high-quality fibre in place of the noisy copper found in Ethernet connections, effectively isolating hi-fi systems from interference. The kits are placed between residential routers and hi-fi systems, and allow the technology to isolate audio networks from residential networks.
The kits are based around ADOT’s MC01 media convertor, which converts the (copper) RJ45 Ethernet cable from the router, to a high-quality SFP fibre connection. Streaming devices already equipped with an SFP input, such as the Melco Audio S100 data switch, can readily accept the fibre connection, however, other devices can also benefit, simply by adding a second MC01 media convertor linked via optical fibre cable.
The ADOT project is led by Melco Audio’s Surrey-based UK and European distributor, ADMM, to optimise the functionality of audio over fibre. ADMM, along with a team of Melco users and technology partners worked to establish the best performance from the technology, knowing that the total isolation of copper-based networks using optical fibre brings immediate sound quality benefits.
ADOT technology is fundamentally straightforward: the Ethernet cable from the router, which normally connects to data switches feeding hi-fi systems, is ‘broken’ by the insertion of a media converter which converts copper to fibre, which gives the isolation, before the data is converted back to copper, but without any noise or interference.
Three ADOT kit options are available: MC01 Kit 1, 2 and 3. Each comprises a MC01 media convertor, a 1.5 m Duplex fibre cable, plus a matched pair of Duplex SFP fibre adapters. The MC02 kit adds a linear power supply and the MC03 kit adds a custom-built PLiXiR low-noise power supply with three-stage noise reduction.
The only real difference I can see between these ADOT devices and a standard media converter that could potentially impact sound quality, are the addition of the linear power supplies in the MC01 Kit 2 and MC01 Kit 3. Here, the theory goes that switching power supplies can inject electrical noise into your AC power line, which could then make its way into your hifi components through that same AC power line. Of course there are any number of ways to deal with this issue like plugging anything with a switching power supply into a separate AC line from your hifi, and/or using an effective power conditioner for your hifi, which can offer additional benefits.
More from the press release:
All ADOT kits are available now via ADMM (Audiophile Digital Music Masters), the Melco distributor, and supplied with a two-year warranty.
MC01 Kit 1 £349
MC01 Kit 2 £399
MC01 Kit 3 £750
Additional MCO1 convertor (to allow use of a device that does not have SFP port) £179
ADOT fibre is available in 5 m, 10 m, 15 m and custom lengths of up to 200 m from £20
The basic ADOT MC01 package for use with a non-fiber-ready hifi would run £528 (about $745). This includes a pair of converters, a pair of switching power supplies, and a 1.5 m Duplex fibre cable. A similarly equipped piece of kit from TP-Link would cost about $45 for the pair of converters and the cable, and you could add 2 linear power supplies from Jameco for about $15/each. $75, all in. I’m not saying the TP-Link/Jameco kit is the equivalent of the ADOT Kit 2 and Kit 3 packages in terms of effectiveness, all linear power supplies are not created equal, but what I am saying is that the option makes for an interesting discussion.

It’s worth noting that this kind of noise means absolutely nothing in the digital realm. The Ethernet protocol is designed to deal with noise, and as we all know, data transmission in Ethernet networks in damn near perfext [footnote 1].
Company Website: ADMM
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