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Firewall Module

Date Added: 02/11/2026 by Jens Thorsen
Firewall 640x Stellar review

"Black Diamonds" with Stellar Performance

I have now been using five Black Diamonds (aka Stellar Firewalls) in my system for quite a while and would like to share some thoughts about them 🙂

I started out with three units, one in front of my LessLoss Distributor (where it replaced a C-MARC 640x Entropic Firewall), one in front of my streamer, and one in front of my DAC/preamp. That setup clearly showed what those black gems do - improved openness, clarity, detailing, soundstage, etc., the C-MARC 640x Entropic Firewall on steroids!

But with only three units, I began wondering if I had them in the right places ...

My "source chain" is completely digital, starting with a standard router (supplied by our internet provider) - well, it's not really that "standard" anymore, as I replaced its switch-mode supply with a good linear power supply that feeds DC to the router via a handmade cable made with LessLoss Large wire. Both the LPSU and the DC cable I made gave substantial sound improvements. The upgrades at the router end were all done quite a while back and were later supplemented with a C-MARC 640x Entropic Firewall and a Prime cable to feed the router LPSU, offering yet another sound improvement.

Next down the line comes my audiophile switch. It has a built-in LPSU and is fed by a C-MARC Classic Entropic power cable and a C-MARC 640x Entropic Firewall.

After the switch comes the Stack Audio Smoothlan Regenerator, which is powered by an external linear power supply. The LPSU is fed from the LessLoss Distributor via a Groneberg Quattro power cable.

At the end of the source chain, I have an Innuos Zen Mk3 streamer (with some modifications, like internal LessLoss Large power wiring). Power to the streamer is coming through a C-MARC Entropic power cable, and (as mentioned above) a 640x Stellar Firewall.

Considering that all the power supply improvements in my "digital" supply chain had given me improvements in sound quality, I started thinking that it might be worth trying out a Stellar Firewall in front of the router's LPSU. But there was a problem. All three Black Diamonds were in use. Also urged on by a friend, who had tried a Stellar Firewall on his own router LPSU, I decided to move the Stellar Firewall on my Distributor to the router LPSU, just plugging the Stellar power cable from my dedicated wall outlet directly into the Distributor instead.

Frankly, because I was removing the Firewall from my Distributor, I was expecting a so-so result from adding a Stellar Firewall to the router LPSU. However, doing this was a marked improvement!

After that improvement, it was clear to me that the so-called "digital" supply chain was much more prone to disturbances on the power side than I had imagined, and I subsequently obtained Stellar Firewalls for both my audiophile switch and the LPSU for my Stack Audio SmoothLAN Regenerator (got one from MusicMagic and one from another friend, who had "overdone" the number of Stellar Firewalls that he needed). Each Stellar Firewall added was a clear improvement (and so was replacing the Groneberg power cable with a C-MARC Classic Entropic power cable 😉).

In my opinion, there are two important takeaways here: 1) The importance of removing disturbances from our "digital" supply chains cannot be overstated, and 2) those Black Diamonds must be as close to each unit as possible for best effect (no news for you on that one 😊).

It should probably also be considered that there are already very capable Firewalls inside the LessLoss Distributor, and that my Distributor also has 8 x BlackGround modules installed.

Keep up the good work!

Jens
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LessLoss History From the Very Beginnings

LessLoss started its business on Audiogon in late 2007. Within the first couple of month, word about LessLoss spread like wildfire among Audiogon members. Here is the feedback received from our clients during our first year of operation. This is from even before we had our own website.

Louis is one of the best in the business, truly professional and very fast production and delivery. I am very satisfied by your superb service. Many thanks.

Positive by Buyer Sebastian (135) on 07-29-2008

Excellent transaction with Lessloss on dynamic filtering power cord. Good communications & fast shipping. A+++++

Positive by Buyer Sennett (45) on 07-03-08

Bought 3 pc's from Liudas in Jan/08. Outstanding product as advertised. Performance is everything and more than I expected. Kudos to Lessloss cable for a great product. Very highly recommended...A+++

Positive by Buyer Phillykid (33) on 06-19-08

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