My dCS dealer has recommended I try ADOT (https://www.audiophiledigital.co.uk/adot.html) for better isolation of incoming ethernet leading to supposed improvement in SQ particularly for streaming Qobuz. Sounds like extra complexity to me but interested to hear if anyone has experience they can share?
Several folks on the forum are using similar optical converters. Looks like exactly the same one you can buy on Amazon for $20. I hope they’re not charging much more than that for the audiophile marketing 
I’m using a Cisco switch with a built in optical interface connected to one of these adapters, which is then connected to my Vivaldi Upsampler with Cat 7. The company you linked does appear to provide power supply upgrades for the adaptor, so that may be useful. Of course you can also buy the Amamzon one and get your own linear supply for it. I’m powering mine with an Uptone LPS 1.2. I set this up more for fun than anything else. I can’t say it made any definitive difference to the sound.
Some folks swear by LAN tweaks and others use the most basic LAN setup happily. There are several threads on this forum already discussing this. Technically speaking no matter what tweaks you apply to your LAN the data will arrive exactly the same to your dCS component, it’s impossible for any tweak to impact this (in a positive way, anyway). The other argument for tweaking is to isolate electrical noise on the LAN from your component. Per my understanding the Ethernet specification alread does this, but as audiophiles we can’t help but try to do better
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I would also recommend trying this.
Well I did get one of those ADOT packages about 18 months ago. I had read several articles and comments from hifi reviewers (notably Andrew Everard in Hi-Fi News) and others on various audio bulletin boards, that an optical link had clear SQ benefits over the usual CAT cabling.
I knew nothing about optical and as the ADOT package had just been announced offering a complete starter pack, I thought I’d give it a go. And yes I must totally agree with your dCS dealer, it did indeed significantly improve SQ - especially from streaming. But I also agree with Jeff that all the components you need can indeed be obtained more cheaply from Amazon and other networking suppliers. But of course, you must know what you need and how it all connects together.
For me the value of ADOT was the excellent technical support. I was a complete newbie as far as optical was concerned. And their very helpful support guy talked me through everything - the options and alternatives, trouble shooting, types of connection, optical cabling, etc. Yeah, you can get the basic components for a lot less on Amazon, but good luck trying to get any worthwhile support.
IMHO, if streaming is an important part of your listening - and I’m a great Qobuz fan myself - an optical link is essential for the best SQ. It doesn’t add much complexity and the optical fibre cables, being smaller, are less obtrusive and easier to route around doors and coving etc.
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Dear Martin,
Noting you got excellent support, I wonder if you could help my friend in this post:
By the way, I want to try the ADOT too.
Thanks
Paul
Well I wouldn’t have the temerity to masquerade as an expert, but I can tell you what I did if that’s any help. When I initially received the ADOT kit, I set it up following the technical note supplied in the box. And, of course, it didn’t work… Pretty much the same result as your colleague. This prompted my first call to the support guy.
I had set the dip switches on the MC01 unit (which is the media converter) for 100Mb/s, as recommended in the technical note (‘best for sound quality’ it trilled confidently). But in talking to the support guy it turns out that a lot of equipment does not work properly with this setting and anyway it doesn’t make that much difference. So basically the take-away was - turn all four dip switches to their off position and leave well alone. I suspect the dip switches are an attempt at product differentiation - a bit of a gimmick perhaps.
Anyway, with the switches set to off it did work. But I was a bit disappointed with the result - it didn’t sound much better than before. Again following their technical note, my initial set-up had the MC01 connected to the router with a short CAT cable, then the supplied 1.5m OM2 optical fibre cable connecting to the optical inputs of the S100. Then from the S100 to my listening room (which is separate from the room with the network gear) I had 15m of CAT cable.
In talking it through and thinking about it a bit, I decided to reverse the configuration. I now have the S100 connected to the router with a very short CAT cable, then a 15m run of optical cable to my listening room where I now have the MC01. The MC01 then connects to the dCS by another short CAT cable. Fortunately OM2 cable is easy to obtain and inexpensive.
My first listen was a genuine wow moment - clearly much better. Without lapsing into sophistry, every aspect of SQ was just so much better. Streaming from Qobuz now at least as good, if not better, than the best CDs.
Other things to check are that the transceivers are connected properly - you have to push them in quite firmly. There is a special plug for the transceiver on the MC called an SFP cage. You can check that all is connected by reference to the LEDs on the unit. (SFP prosaically just means ‘small form-factor pluggable’). You need LC to LC OM2 multimode cable to use with the supplied transceivers.
Hope it helps…
Thanks All for the helpful input. It seems that a fibre link could help SQ. My only concern from the comments is that ADOT seems very overpriced for the job and much better value components are readily available. I need to do some further research on that.
I run a fiber from my switch to my Rossini. The fiber/ethernet bridge on the Rossini side is standard and powered from a linear power supply. Works well. I do it because it naturally provides more glavanic isolation but more importantly because I don’t want a lightning strike or some power surge to damage my Rossini.
Thanks Miguel - do you mind sharing which fibre/ethernet bridge and LPS you use? Was there any special setup needed? By the way, aren’t you just as likely (or unlikely) to get a lightening strike via the electrical power cable as via ethernet?
Switch side:
https://www.amazon.com/gp/product/B0716XT1QT/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
Rossini side (mostly because I want to have an extra ethernet port, note this one doesn’t come with the SFP transceiver so you need to add that or get two of the above instead):
https://www.amazon.com/gp/product/B07YJC54VJ/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
LPS:
Also, I had the LPS lying around. I don’t think this is critical, the power supplies that come with the bridges are fine.
Setup couldn’t be simpler: you plug it in and it works - nothing to set up.
As for likelihood of electrical surges, removing one source is useful (my entire building is wired with coax/ethernet). Yes, the powerline is another source of electrical surges and I have surge protectors there. Just a little more isolation gives me some piece of mind.
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My fiber setup- approximately from memory:
2 Cisco 2960’s - ebay I recall less than $100 each
2 Cisco fiber cages ebay - about $10 each
Fiber cable Amazon - about $10
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I thought I would share the following feedback I received from Alan Ainslie of the UK ADOT distributer explaining higher cost of their ethernet/fibre bridge units compared with standard equipment widely available off Amazon, et al:
“Melco is manufactured by Buffalo technology in Japan. ADMM is Melco Distribution and support outside of ASIA – I was closely involved with the project initially working directly for Japan. Melco is all about extreme sound quality and our users focus on audio performance as you might expect. A couple of years ago some users in Japan were using Buffalo Media converters and SFP with the newly introduced Melco S100 switch and reported consistent sound quality improvements. Although not Melco branded we looked at importing the Buffalo devices and purchased a couple of sets. I was not impressed with the audio improvement, but measuring the effect on packet timing and consequent audio sidebands there was clearly something to look into. Some other Media Converters were actually worse than simple Ethernet cable. And measurements explained why. So we looked at many manufacturers and got to understand – the main difference is the chipset used in the media converters. However, the best chipset from sound quality point of view was old tech and not favoured by the IT industry who are looking for extreme speed and low latency. This does not benefit audio. So we knew what was necessary to find best sound quality, and in the end worked out the best combination of media Converter, SFP and fibre. The remaining issue was to get consistent supplies of old tech hardware, in production quantities with proper certification and QA, and we modified product from one vendor to suit our specific needs. Quantities were low, and cost consequently relatively high. The IT manufacturers expect production quantities weekly that represents ADOT sales for a couple of years! We then needed to neatly package as a set, provide instructions, get safety approvals, find supplier of linear supplies rather than SMPS – and the rest is history. We uncovered some interesting truths – less than 1m of fibre is a problem for audio. Good engineering explanation but still a surprise. Single Mode is only marginally superior than multimode. But we do offer a single mode alternative. Linear supplies were essential not only for the media converter but to avoid poisoning the supply to the rest of the system. IT Media converters actually vary a lot in cost and we are not out of line I feel – especially when comparing that the IT market demands low margins and a 90 day warranty, whereas the HiFi market requires better dealer margins and a proper warranty. Even so there really are many good quality IT media converters that cost significantly more than ADOT, but certainly there are many commodity products that are available for much less. This is not surprising really. In the same way as there are a great many DACs available for a fraction of the price of a dCS – the only difference is the music. Trust your ears – if the difference is not worth it please do not spend the money – buy some downloads instead. Hope that helps. It is engineering rather than snake oil, but we are looking at small quantities of niche production compared to massive production of commodities.”
Here is a recent review of ADOT which is interesting - https://www.hifipig.com/adot-mc01-fibre-network-kit/
I would really love to hear what measurements he’s talking about. In terms of the packets and data you get at the DAC ALL ethernet will be exactly the same untiless it’s heavily malfunctioning.
Of course he needs to provide some reasonable sounding exaplanation for their profit margins, but don’t be tricked!
If on the other hand, it’s the quality support you’re looking for, that’s a perfectly good reason to go with this product. Don’t believe the rest of this for a minute.
Keep in mind the original prices for the Cisco gear listed above were in the thousands of dollar’s
As update, I borrowed an ADOT MCO2 kit from my dealer to test whether it offers any benefit in my system - in path direct from router to Rossini. I have to report my initial impressions are positive. Very easy to setup and worked out of the box at the recommended 100Mb/s setting. I have always found streaming from Qobuz somewhere between 15-20% inferior to CD (as we know, Rossini CD is extremely good). With ADOT streaming from Qobuz is now very close to CD. Given that I am forced to use powerline adapters owing to domestic setup in my home with router in a different part of the house to HiFi rack and no cabling, I regard this as quite an achievement. As per discussion, maybe I can put together individual components from Amazon for better value. However, given packaging and support benefits, I am inclined not to bother and go ahead with a purchase. Hope that is of interest.
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The ADOT from my inspection inside is identical
to TP-Link multimode or Singel mode 3D duplex converters.
100 megabit/s is the best way in singel mode setting.
Almost all brands with the same case is TP-Link
https://www.amazon.se/fiberomvandlare-europeisk-strömförsörjning-SFP-sändtagare-leveransen/dp/B08ZN8DNV5/ref=asc_df_B08ZN8DNV5/?tag=shpngadsglesm-21&linkCode=df0&hvadid=476620675629&hvpos=&hvnetw=g&hvrand=17388616855190488455&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=9062465&hvtargid=pla-1392240674534&psc=1
And i have tested diffrent linear and battery packs with 9v 1 A including the uptone 1.2 and you get different sound characteristics.
With the stock SMPTS you get a decent sound neutral but slightly harder sound, but you will pollute the rest of your components.
With a Linear supply you get a slightly warmer sound and no noise pollution to the rest of your gear.
Uptone super caps power supply you get a very warm and slightly dull sound.
Li-ion Battery charging pack you get the best neutral sound but slightly less shimmer vs Linear power supply.
So you can you can tune your own sound, in a good or bad way…
It’s curious, I’ve not looked inside. But leading on from the discussion on this thread, just for fun I thought I’d try replacing the ADOT MC with a generic IT/data comms MC (not the cheapest, but still inexpensive). It was easy to test by simply unplugging the SFP transceiver from the ADOT and inserting it into the generic unit plus swapping over the Plixir 5v DC LPS.
I was confidently expecting there to be no detectable difference. So I was surprised to notice not only a difference, but also that the ADOT sounded better. I left the generic unit in place for a day or so to remove any possible burn-in type issues. The generic unit introduced a slight glare or electronic glaze, particularly noticeable on brass or orchestral strings.
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Placebo is one thing, it is also important to compare the exact same spec on the units nevertheless brand on the outside👍
But if the brass got more glare then i recomend to keep the ADOT or find another Media Converter, like the one i linked to that got the same internals as the ADOT singel mode version. 
You are paying for the linear powersupply and because ADOT are buyung these components from TP-Link and need to put on margin to make a profit
Hi Fredrik,
I’m not seeing any dip switches on the TP link version, not sure if it makes any difference but it suggests it’s not identical?
Regards, Mike.