Matrix Audio SI-1 Network Isolator


A recent discussion on the value of network switches by @fire_water  rekindled my curiosity about revisiting optical isolation. As someone who leans toward minimalism, a single-box optical isolator was the prime draw and to see if newer devices offering further improvements over my existing optical isolator. 

For context, my front end is built around 3 chassis Merging Technologies +PLAYER / Merging Technologies +CLOCK / Merging Technologies +POWER which is already extremely low noise, highly resolving, and very “studio honest,” reflecting its roots in professional high-resolution recording and editing. It doesn’t gloss over upstream shortcomings—if anything, it exposes them. As a result, any change ahead of it is easy to evaluate.

To be fair, my existing Telegärtner OPTO BRIDGE 1000M already performs very well—delivering a cleaner background, lower noise, and solid isolation. No complaints there except it is powered by an external LHY linear power supply…extra cables plus more real estate :-) 

So how does the SI-1 compare?

In my system, the SI-1 builds on Opto Bridge foundation with:

  • A further reduction in noise floor
  • Greater image density and depth
  • Improved microdynamics and sense of flow
  • A more natural tonal presentation without sacrificing resolution

The biggest difference?
With the Telegärtner, the presentation was clean and relaxed.
With the SI-1, it becomes more organic, fluid, and musically coherent.

My take:
Telegärtner = excellent isolation
SI-1 = isolation plus signal refinement (regeneration) by breaking ground noise and eliminating EMI/RFI riding on Ethernet. 

In a highly resolving system, that extra layer makes a meaningful difference.

Here’s the rub guys, not every system truly benefits from an audiophile Ethernet switch or an overbuilt router. That’s been my experience after introducing optical isolation into the chain. Once I did, even a high-quality switch like the Telegärtner M12 Gold Switch became redundant.

IMHO, optical isolation is essential for any serious streaming setup. The SI-1 doesn’t feel like a tweak, it comes across as a final-stage refinement, allowing your streamer to perform at its full potential and reveal what it’s genuinely capable of.

Here is my signal chain, 

Apple Router →  SI-1 → Streamer (Merging stack) using a pair of FTA Métis LAN cables. 

https://www.matrix-digi.com/product/125/SI-1

lalitk

@grannyring --

Congrats on your acquisition of the SI-1. It will be interesting to learn of your findings once the unit has exceeded 150 hours of use, so please report back - should you care to.

Optimization of an existing setup's different main component categories are interesting journeys to embark on to extract a fuller potential. Sometimes what's sought to be improved is really already there, i.e.: albeit not yet fully exploited or fleshed out via due measures, whatever they may be.

To me the impact on sonics (not least its nature) with the implementation of the SI-1 came as a surprise. Next up will be finding out what the effect of a Master Clock to my digital source will be - something I've not yet been too keen on investigating in more detail. Something tells me it may be another essential move in the right direction (like the SI-1). 

Grannyring, any changes after the 150 hours?  Is there a reason you guys are buying the Matrix Isolator over the Matrix Swtiches?

Lalitk, thank you, that clears it up.  I order the S1-1 Isolator, but they sent me the SS-1 Network Switch instead.  I don’t need all of those ports, just one device is in use, my streamer.  I didn’t know if there would be sonic advantage of a switch over an isolator.  I’m going to send the Matrix Switch back and get the Isolator coming 

“I didn’t know if there would be sonic advantage of a switch over an isolator.”

@kclone 

In my experience, when using a single streaming device, an optical isolator is all that’s needed, and the improvement is significant enough to justify its cost.