This took longer than I thought but here are the results of some comparisons I did:
Several of my friends and forum members — Kennyb123, Ray-Dude, Always Learning — and I have been carrying on a back channel discussion about FMCs, SFPs, the EtherRegen (ER) from Uptone Audio and the Optical Module (OM) from Sonore/Small Green Computer. We’ve each heard some of these devices in our own systems but none of us except Kennyb123 have heard them all head to head. Through the generosity of these folks I was lent the pieces I was missing so I could do a comparison in my own system as an Extreme owner and hopefully share some insights from my perspective.
My system is listed in my current signature.
My LAN is fairly simple compared to many peoples’ setups:
DSL modem (WAN port) > copper jumper > Synology RT2600ac WiFi router > copper jumper > TLS OXCO switch > copper > AV system, and copper > Thecus network attached storage (NAS) device. All of these devices are in one room across the entry foyer from the living room where my stereo is located.
I have WiFi turned off in the modem, firewall enabled, domain name server (DNS) enabled. WiFi is turned on in the Synology RT2600ac and it is linked wirelessly with a Synology MR2200 mesh router upstairs. The MR2200 provides strong WiFi coverage upstairs and is linked via copper to an AV system in the master bedroom.
The DSL modem is powered from one rail of an Uptone Audio JS-2 linear power supply, a Startech FMC is powered from the other rail. The Synology RT2600ac is powered from an inexpensive variable linear power supply. The NAS uses its stock onboard SMPS. All of these power supplies are plugged into a Shunyata Research PS-8 power strip using a Shunyata Alpha Digital power cord to the wall. Additionally, a Shunyata Venom Defender is plugged into one of the PS-8 receptacles.
No particular vibration control is used other than original Stillpoints cones under the JS-2, Vibrapods under the cable modem and the FMC or device under test (DUT). I haven’t noted any particular improvement in sound quality with these vibration control devices, but I have them and so I use them.
My baseline connection from LAN to Taiko Audio Extreme server is the one recommended by Emile early on — Startech FMCs and Startech SFPs (1550nm 80km), LC LC fiber and copper jumpers. I’ve been using these even before my Extreme arrived to connect my previous Innuos Zenith server to the LAN, with the addition of another Startech FMC and jumper at the Zenith.
With the arrival of the Extreme, the feed from the LAN became:
DSL modem > copper jumper (Sablon ethernet cable) > StarTech FMC/Planet Tech SFP with -10dB attenuator > fiber > Startech SFP with -10dB attenuator/Extreme
My initial plan for testing involved comparing the baseline feed from LAN to Extreme to the following:
DSL modem > copper jumper > ER “B” side/ER “A” side/Startech SFP w/-10db attenuator > fiber > Startech SFP with -10dB attenuator/Extreme
DSL modem > copper jumper > ER “A” side/Startech SFP with -10dB attenuator > fiber > Startech SFP with -10dB attenuator/Extreme
DSL modem > copper jumper > OM/Startech SFP with -10dB attenuator > fiber > Startech SFP with -10dB attenuator/Extreme
Then repeat without attenuators on the SFP ports.
Finally, repeat again, this time substituting Planet Tech SFPs (1310nm 20km) for the Startech SFPs. Again, with and without attenuation.
I kept all other devices, including power supplies the same and only varied the devices used in place of the Startech FMC. Obviously, the SFPs stayed the same on each end for each trial.
Additionally, I used a ground lead from each device to an AC earth ground; both the Startech FMC and ER have provisions for this, I backed a case screw out a little on the OM to use as its ground point. Like Rajiv in his experiments with the ER, I didn't hear any particular advantage or improvement using the ground lead with any device -- perhaps because I have also removed all SMPS' from my equipment in the computer room/office (my NAS with its internal SMPS has been off since copying all my music to the Extreme). Since the ground wire wasn't hurting anything, I left it attached for each trial.
As indicated above, in the case of the ER, I tried it as designed ("across the moat”), "B" to “A", as well as copper in/fiber out on the "A" side only.
I gave each device under test a minimum of 24 hours powered up with Roon Radio playing and my amplifier off before listening, with the exception of the ER tests which I performed back-to-back without additional warm up time after the first 24 hours. Any other device I thought I might want to quickly A/B against the DUT I kept warm by using an inexpensive variable linear power supply from Radio Shack.
So, that sets the stage with the test conditions and protocol. Next post — what I heard.
Because of the number of permutations involved I kept the streaming tracks used for the comparisons to a minimum to in an attempt to keep the overall project manageable and importantly, to keep my sanity. Like any audiophile, I unavoidably end up listening to sound as much as music when doing comparisons — what improved, what didn’t improve? But my tolerance for this kind of listening is pretty low and I would much rather relax and just listen to music once a certain minimum acceptable sound quality is reached. Too much concentrated A/B/C testing and I start to lose the will to go on living.
The three streaming selections I used are:
1. Brenda Fricker, Anuna, Never Give All The Heart from The Chieftains "Tears Of Stone" 16/44.1 Qobuz stream
2. Brian Bromberg, The Saga Of Harrison Crabfeathers, "Wood" 16/44.1 Qobuz stream
3. Clifford Curzon, Benjamin Britten/LSO, Mozart Piano Concerto No. 2, Allegro 16/44.1 Tidal stream
With 2. and 3. I used two different sections in each track rather than playing the whole long track through each time. Each of these recordings have places where the digital transfer can sound anywhere from hot to irritatingly bright or hard if everything isn’t up to snuff in the digital path.
A word about what I listen for when doing this kind of test. I'm very sensitive to harshness, hardness and unnatural brightness. I listen for tonal balance and saturation, low-level detail, depth, width and height (particularly depth), and dynamic swing. And generally, I also try to listen for an undefined overall *enjoyability* -- would I be happy listening to my system sounding like this for hours, or would I be unsatisfied and restless?
I've found that for whatever reason, a recording on the edge of being hard or harsh sounding will be tipped over that edge and become hard to listen to by less than excellent digital performance. Sibilant sounds, cymbals, and other high frequency instruments can quickly go from brilliant to bright to hot. As the top end hardens and higher frequencies become more prominent everything seems to flatten out. My test recordings tend to emphasize this in places and so represent a worst case scenario. There is still lots of music that will sound fantastic with any of these configurations though.
So, without further ado --
First off, my feeling is these LAN optimizations are audible and are worth pursuing, particularly since other than the power supplies and one of the devices under test (ER), they are fairly inexpensive in the audiophile scheme of things. However, I am also in general agreement with other Extreme owners that the largest benefits are gained from premium power cords, USB cables, and vibration control. Network optimization is an order of magnitude lower in effect than power, USB and vibration.
As a general conclusion, in all cases I preferred using the Planet Tech 1310nm 20km SFPs over the Startech 1550nm 80km SFPs. This was regardless of device (ER, FMC or OM) and regardless of attenuation used or no attenuation at all. In fact, in some circumstances the choice of SFP made a bigger delta than choice of device (ER, FMC or OM). Likewise, I found I always thought using -10dB attenuators on the receiver ports of the Startech SFPs to be a necessity, or they sounded edgy with any of the devices.
The most cost effective and must-do item from all my experimenting is replacing any Startech SFPs with Planet Tech SFPs. The Planet Tech SFPs made every device (OM, ER, FMC) sound better in my system. At $23.90 USD the Planet Tech SFPs are a bargain.
Specific device results --
Any of the combinations, even the nominally last ranked, are still much better than the 50 feet of copper ethernet I originally used between LAN and server. Also, moving my feed to the Extreme all the way upstream to an ethernet port on my DSL modem and having everything else in my LAN downstream on the other side of a WiFi router fed from the modem's WAN port, was as large a positive improvement as choice of device.
1. Last place, but still very honorable mention:
The combination of Startech FMC/Startech SFP is one I lived with even before I took delivery of the Extreme. It was a large improvement over a long run of copper ethernet from LAN to server. I did find -10dB attenuators on the receiver ports tamed some brightness which might have been caused by overdriving the SFP receivers with the powerful 1550nm lasers over a very short fiber link.
The Startech FMC can sound very good, but there is better out there and it came in last of the three devices I tested. A Startech FMC with Planet Tech SFP and no attenuators sounds better to me than the all-Startech combination of FMC and SFP.
However, the Startech FMC configurations sound, as someone else on one of the Internet forums observed, somewhat mechanical in nature compared to better combinations.
2. Good, and Better:
EtherRegen (ER) "B" to "A"/Startech SFP/-10dB attenuators, and Planet Tech SFP/no attenuation --
The ER "B" to "A" across-the-moat configuration is less mechanical or electronic sounding than the Startech FMC combos. It also nicely ameliorates any tendency of edgy digital transfers to tip over into brightness or harshness. However, with the Extreme it sounds too polite and sounds smaller and less energetic than any other combination. The Planet Tech SFP helped with the clarity but didn’t cure the small stage size and lack of dynamics.
3. Better, and tied for Best:
ER "A" to "A"/Startech SFP/-10dB attenuator, and Planet Tech SFP/no attenuation --
ER in the "A" to "A" configuration brought back a good part of the dynamics and life and scale of music. The Planet Tech SFP sounded a little softer than the Startech SFP, but in either case the "A" to "A" ER brought back some of the edginess too. This was slight however, and for a person who needs a switch rather than an FMC, the ER is a cost and sound-quality effective choice. And, from the preponderance of reports, if a non-Extreme owner can use it in an "A" to "B" configuration, it might be the best sounding option of all.
4. Best in my situation:
Optical Module/Startech SFP/-10dB attenuator, and OM/Planet Tech SFP/no attenuation --
The OM is perhaps the most transparent to, or maybe I should say the most dependent on the SFP it is paired with. With the Startech SFP even using attenuation, the OM can still be a little edgy. But it sounds big and bold and full of life, if just that little bit hard on top with less favored digital transfers. As a result, it sometimes sounds a little flat and a little forward when challenged with brighter recordings.
Paired with the Planet Tech SFP and without any attenuation, the OM retains all of the life and dynamics of music without any objectionable hardness on top, and with a subjective sense of more depth, dimension and space. It doesn't hide what recordings are, but it doesn't exacerbate their imperfections either. To my way of hearing, it strikes just the right balance in the context of my system and my tastes. I had one of those, “Ahhhhh, this is good!” moments when I started listening to the OM/Planet Tech SFP combination.
I wound up my tests by comparing streamed tracks to their twins residing in local on-board storage, and also tested the claim that with the Extreme and an optimized network, high-resolution (24/96, 24/192) streamed music can beat standard Redbook resolution (16/44.1) stored on-board the Extreme.
Listening to the same resolution streamed to compared to local playback, I thought local playback to be a bit better -- a little cleaner, a little darker and a little more depth. But it is very close and streaming certainly doesn't suffer for the comparison. I can listen to music via the Extreme and Roon Radio streaming all day long and never get tired or restless. Every so often a poorly recorded or digitally transferred track will come up, but that can happen regardless of medium.
Streaming higher resolution tracks and comparing them to their standard resolution, locally stored counterparts proved a little trickier. It's difficult to determine in many cases whether the mix was also tweaked when the source recording was remastered to higher resolution; in the case of MQA high resolution, MQA processing may be affecting the recording in ways that are sometimes enhancing and sometimes detracting (in my experience). However, over a dozen or so non-MQA high resolution Qobuz selections I found that in the majority of cases I did indeed prefer the high-res streamed version over standard resolution locally stored content.
Once again I'll just say that all of this is very much in the context of my own system, LAN and taste in music and musical presentation. And it appears that for whatever the reason, with an Extreme in the mix some of the unique attributes of the EtherRegen don't come out in the same way they do with other servers. The EtherRegen would be my first choice if I needed a switch in the feed to my Extreme because it is still better sounding than a Startech FMC, or a TLS OXCO switch. However for my needs and for what I value in sonic presentation the Optical Module with Planet Tech SFP has just the right balance.
Hopefully this was helpful, or at least interesting and worth the time spent reading.
I hope everyone is well and taking care of their loved ones in this challenging time.