I recently added a modified Melco/Dela S100 switch to my system. My experience follows.
My first audiophile switch was a modified consumer-grade Linksys SE3008. SOtM changed capacitors, replaced the switching regulator with a linear regulator, and enabled the switch to be re-clocked by the sCLK-EX board in my tX-USBultra. Later, the sCLK-EX was re-clocked by their sCLK-OCX10 master clock. As others have noted, the result was a nice improvement in sound quality.
At some point, we were told that a particular Netgear switch could shunt upstream noise to ground, so I added one before the modified SE3008. Although I could never hear any difference, I left it in place. Much later, I tried a Cisco Catalyst 2960. I heard no change, so I removed it.
I purchased the SOTM sNH-10G audiophile switch a few months after it was released. To be honest, I was put off by the price and was skeptical of its value. I knew from prior experience with my tX-USBultra and sMS-200ultra that I could get much better sound quality using 20AWG solid core Neotech silver wire with JSSG 360 shielding rather than the generic 22AWG stranded silver offered as an upgrade by SOtM. The Neotech upgrade increases openness, transparency, and detail. Importantly, it also adds body to the sound signature. Consequently, my sNH-10G does not suffer much from the thinness that others have noted.
Along the way, I acquired a Mutec REF 10 to re-clock the tX-USBultra and sNG-10G. The REF 10 is a marked improvement over the sCLK-OCX10.
I purchased an EtherREGEN soon after its release to chain with the sNH-10G. During this time, I removed the Netgear switch from my network and noticed an uptick in sound quality. I ran this configuration for a few months before deciding to part with the EtherREGEN and try a re-clocked Melco/Dela S100 instead.
The S100 modifications were made by Pink Faun. They replaced the 25MHz oscillator on the S100 board with their Ultra OCXO clock module. They also removed the internal power connectors and soldered those wires directly to the board. Finally, and perhaps most importantly, they created a 5v input to SEPARATELY power the clock module. In other words, the modified S100 requires two power supply rails: a 12v rail for the switch board and a 5v rail for the clock module.
I would like to give credit to @seeteeyou for the idea of modifying an S100 and to @Nenon for giving me his thoughts and suggestions during my due diligence process.
A simplified representation of my system excluding grounding and power is as follows (apologies for the lack of an easy-to-read flow chart):
NUC7i7DNKE Euphony/Roon Server > Viablue EP-7 Cat 6a > SOtM sNH-10G SE
Synology DS218j > Viablue EP-7 Cat 6a > SOtM sNH-10G SE
Linksys WRT 1900 ACS router > Viablue EP-7 Cat 6a > SOtM sNH-10G SE
SOtM sNH-10G SE* > Single Mode Fiber > Modified Melco S100** > Synergistic Research Galileo UEF Ethernet > NUC7i7DNHE StylusEP > Habst USB Ultra III > tX-USBultra SE* > Synergistic Research Galileo UEF USB > Chord Hugo M-Scaler > Synergistic Research Galileo SX Digital BNC (2) > Chord DAVE > 12AWG 16-wire UniCrystal silver custom headphone cable > HE1000se headphones
* Re-clocked by Mutec REF 10 (Habst Digital BNC)
** Powered by a Farad3 12v and a JCAT Optimo Duo 5v rail. A 100Mbps port is used to connect to the NUC7i7DNHE endpoint.
(Note: A particular Finisar SFP recently has become popular for its added transparency and air. In my system, I found the perceived improvement to be the result of a recessed midrange. I went back and forth several times to confirm this impression. In my system, for this particular application, the Planet Technology SFP is clearly superior.)
In a nutshell, the modified S100 has profoundly affected my listening experience. I have implemented many changes during the past few years, upgrading sources, all types of cables, signal regeneration and re-clocking, power, grounding, and RAM. In a few instances, a tweak or modification resulted in the perception of having acquired an upgraded version of a particular piece of gear. Others were less dramatic but provided welcome improvements in sound quality. None had the transformative effect of the modified S100. Replacing my DNA Stratus headphone amp and Auralic VEGA DAC with the Chord DAVE was the most significant upgrade that I have made to my audio system. The modified S100 is probably the second most important.
I am not a professional reviewer, and finding the words to properly describe what I am hearing has been challenging. To begin, the background is very black. Low level detail is jaw dropping. I hear much more subtle elements in voices and instruments. Reverberation and decay are more apparent. The sound signature is smooth with an extended high frequency response that is not the least bit fatiguing. Images and soundstage are more focused and coherent. The acoustical space is more easily discerned. Tonality, density, and resolution are outstanding.
I consider the sNH-10G to be my baseline switch. Adding the ER modified the sound, primarily adding body while sacrificing some of the transparency, detail, and spatiality which are the hallmarks of the sNH-10G. The net result was to tune my system rather than take a major step forward. Replacing the ER with the modified S100 is an entirely different experience. As I have attempted to describe above, the modified S100 elevates the sound quality to dramatic new heights.