Entreq Olympus Infinity and Olympus Minimus review part one

One of the subjects, that can easily stir the conversation is certainly the ground box. There is almost a fanatic following to the grounding and the opposite movement can be similarly energetic… 

Yet, for many audiophiles with various degree of systems, the grounding becomes an indispensable accessory for the balanced system performance. I’ve been following the grounding for a long time and witness many their application in various setups as well as trying some of them in my reference setup. Honestly saying, the impact is not always of night and day designation, but I did also experienced a major shift in performance at few occasions that cannot be labeled as as subtle changes. 

At this year’s Munich High-End Audio Show by a chance I was invited for a drink by my friend Pierre Costers form BELHiFi. There was also a Per-Olof Friberg, the owner of Entreq and despite the chilling weather we started an interesting discussion that led to many common points and views regarding the high-end audio.

A few weeks later Per-Olof contacted me via email with the great news. He sent out three Olympus Infinity and one Olympus Minimus ground boxes and variety of grounding cables for me to experiment.

As many of you requested for me to dig deeper into the grounding and share my experiences, here is a first look into the subject matter.


I’m sure that most of you need no special introduction to the iconic Swedish brand, but I think it’s important to refresh the memory of the Entreq philosophy…

As you study our product lines you will see a commonality in approach and execution of the solutions. These solutions have been garnered over 18 years of not just theoretical analysis, application and understanding of materials and their inherent effects, but through new un-expected discoveries during the testing and the all-important listening process. The years have truly taught us that the more you assume you understand the more you NEED to explore and stay open-minded to solutions that simply have yet to be realized. It’s a lot of the small details and the nuances that make all the difference.

We have concluded that if you THINK you have a complete understanding, you have already lost your way! There is always more to learn. Always!

We are all unique individuals with differing tastes, who have different criteria when judging musical value. Therefore there are no “this is the best” or “this fits everybody” products. As a manufacturer, we can simply offer you good products, from sound choices, built on a foundation of knowledge and experience while offering a degree of personal flexibility and tuning.

From our full range of Ground Box’s and the all-new Infinity range of Ertha cables, we feel we have taken sound reproduction to a new level. The only way to understand how natural a system can sound with these products is to try them for yourself.

“That which can be measured is not so important, and that which is important cannot always be measured”

There is quite a lot of truth in this statement, even if it is not completely correct.

We at Entreq trust more what we hear and experience rather than purely what our test equipment tells us. If something sounds better than something else, then it is. It is that simple even if you perhaps cannot fully explain it scientifically, at this time, with measurements.

We remember back in the 70”s when everything was simply measured in the laboratory. At that time it was supposedly the DIN measurement 45 – 500 that supposedly told us all we needed to know. It was DIN Watt, IM dist, HM dist that governed whether something was good or not. If it didn’t measure well enough, it was simply solved with negative feedback and that was it!

Many times the equipment sounded awful but hey the measurements were good, surely it must be good then?

It was a sensation when Matti Otaala from Uleaborg University explained why some amps that only gave 20 W Din 45500 sounded so much better & more powerful than amps that gave 200w.

What we are trying to say is that sometimes just because you can’t define a “measurement” for a sonic improvement at this moment in time because we either don’t know what we are specifically looking for or have the equipment to measure the unique properties, doesn’t mean that our human ears can’t detect the pleasurable improvement! .

So we intend to continue as we began. You can rely on us to use our extensive knowledge to develop products but we will always use our dedicated team of listeners to ensure that theory meets reality. In our experience, the measurements are actually far less important and rarely pick up on the subtle but essential differences in materials & construction. However, what is important is that we develop a product that you as a customer simply get greater enjoyment from listening to your music. It’s that simple, that’s our goal!


In 2007, after years of research, Entreq launches its first commercially available Ground box – The Tellus  – the Tellus really divided opinions and generally created two groups. Those who tried our grounding system were intrigued and often very excited by the results. The other group just mocked & laughed at the idea of the product saying there was no way it could work. Ironically the second group often never even bothered to listen to the product!
Tellus was the result of many years of testing and the initial attempt to create an artificial ground point for signal earth. Entreq had realized that the grounding plain carried a wide range of pollution that affected everything connected to it. In particular, high-frequency currents seemed to affect the sound very badly. In the beginning, we simply used generic copper cables to directly connect the Tellus to the electronics and our signal cables. But very soon customers began to give them feedback that they were experimenting & experiencing different results depending on the type of cables they used to connect to the Tellus. Good and bad results.
This kick-started a whole new era of investigation and testing over the coming years!
By 2010 Entreq had started to understand far more about the influences that different combinations of materials had on performance and that each individuals Hifi system required a degree of tuning to offer optimal results. At this point, they’ve introduced the Silver Minimus, Silver Tellus, Silver Cleanus and four different lines of Eartha Grounding cables.
Over the years of developing these additional products, Entreq learned far more about grounding. They’ve realized that stray voltages, field effects, and high-frequency pollution can pass in many different directions. These phenomena can be directly compared to how computer virus’s spread, evolve and are introduced.  There are new and different types all the time and they can affect different circuits and systems in quite different ways.
2018 saw the emergence of Entreq biggest breakthrough yet in performance in both Grounding, Ertha cables and the rest of their cable range, the application of Entreq exclusive Infinity Technology. With Infinity Entreq has yet again pushed the bounds of what is possible and taken a huge leap forward. There are now many companies bringing their own interpretations of Grounding solutions to the market but Entreq is assured that they will always be ahead of those that follow. Per-Olof feels the same about Infinity and how it has stretched that margin even further.


To better understand the Entreq way and what’s special about their grounding devices I’ve asked Per-Olof Friberg a few questions…

Why grounding?  
The easiest and simple answer is, “that is the easiest and cheapest way to get an easy flowing, uncompressed natural sound.
For us, a clean and effective ground point is one of the most important factors in ensuring the best possible sonic platform for any HiFi system!
We normally say 220V 50Hz alternative 110 V 60Hz. But in our opinion, there are a lot more frequencies on the power net. These are caused by the way we connect zero and protective ground together in the main central/fuse boxes. Most things these days run on electricity. Current goes in and current goes out of devices and lighting fixtures of every kind. All of these make the current messy. Not least computers with their switched power units, chargers for e.g., mobile telephones, all the halogen and LED lighting, dimmers, etc. all cause a great deal of high-frequency noise and stay voltages. This noise always seeks the easiest path to the earth. And since this can be everything from 50-60 Hz to very high-frequency, but weak, currents, it is not always certain that the path of least resistance is via the protective earth. These currents instead can find dishwashers, laundry machines, countertops with water pipes, your HiFi rack and your stereo set with all the cables and devices as more attractive paths to the earth. Moreover, these stay voltages often generate very large magnetic fields that absolutely have an influence on sound reproduction.
One big problem is that the protective ground many time are overloaded or not constructed to handle these pollutions. It can handle a real “bang” of 110-220Volt and X  Watts without any problems, but when it comes to these small currents of some Milli V  with the very high frequency it doesn’t catch them. So instead these will flow around in the power system searching for a place to ground. And in fact, the protective ground can leak back a lot of pollutions to the power net that instead go to fix your HiFi system with all the cables and magnetic fields and load up and rest there in their search for ground. Our ground boxes / Eartha cables are designed to resemble and work like a bit of Mother Earth in concentrated form and offer the simplest and fastest route for this high-frequency noise to reach an earth point. Since such are very high-frequency weak currents, it is not necessary to have a lot of mass;  but it is important that the cables are optimized for this high frequency and the ground box be a purely attractive earth point. The construction and choice of materials in the earth box has a crucial effect on the result. In part, the minerals and metals involved have an effect, but the relationship of proportion and distance between them also affects the result.

When you connect your system to one of our ground boxes you offer this high frequence stay voltages a ground point where they can find peace instead of flowing around in the system. 
What makes Entreq ground devices so different from the competition? 
We start work with grounding 2004-2005. 2007 we released our first ground box Tellus. And it´s still this Tellus our competitors use to compare their own products with. 
During all these years we have spent many 1000 hours on testing and this way we learned so much more about grounding the practical way than any other company. I don´t think there is any other company that comes even close to our practical knowledge. We test new materials and mineral mix all the time and we have a very, very close relationship with many of our customers /users who give us feedback about how it works in their systems. 
I for sure can say that no one else comes close to our practical know-how and knowledge. And that is much because of our customers. In one way you can say that all our products are a result of the feedback we get from our customer/ users.  
How much improvement you would say it’s possible to gain with proper grounding scheme? 
Very difficult to say. But one thing is for sure. If you have big problems with high frequency pollutions, you never will be satisfied and it will never be good, no matter how much money you spend on Amps and Speakers if you don’t ground them in a proper way.

Is there a threshold of too many grounding devices being introduced into the system?
Yes, you can put to many and too heavy boxes in your system. You can overground it.
Should grounding connections become an industry standard (also on the speakers)?
Why not?
I think there are many and big benefits with a proper grounding of speakers. There are a few brands that use it today, but I think there is much more to do. Since manufacturers don´t seem to be interested in this (we have been in contact with some manufacturers) we have in fact decided 1 year ago to start work and develope a speaker by our self where we use the knowledge we have got from grounding, racks, and our cables. The result so far is very promising. It´s a very cost-effective way to good sound.


Why grounding most of you might ask? There are still many things unknown when it comes to the grounding and there are different takes about it with two quite strong counterweighting camps. 
With Entreq grounding boxes, there is surely no doubt. They do bring the positive performance shift and in my evaluations so far the differences were not low-key. On the contrary!

It took me quite a while to bring the performance of my reference system to the level I consider balanced and potently performing, but inspiringly, the Entreq ground boxes acted as an eye/ear openers.

It seems, that refining and fine-tuning the high-end audio story remains a life long quest and journey.  Nobody really know where is the ultimate threshold and consequently we cannot neglect the progression in various fields of our industry. A constant push forward momentum is something that other industries are organically accepting and implementing in their discovery of better performance.

Our beloved and still niche profession is a bit slow-paced in this regard, but gradually we’re opening the minds and starting to open up also for a bit more out-of-the-box approaches, that are still considered as exotic and esoteric. Enormous electronic and magnetic noise are surrounding us. Actually, such pollutants are more aggressive by each and coming year. The ether is polluted by all sort of signals (mobile networks, GPS, Wi-fi, etc.) and the mains are non-different.

Switching supplies are one of such heavenly polluters. I can tell you from the personal experiences how much noise just a LED’s switching power supplies can introduce. The complete system performance can instantly turn into a nervously untamed sonic provider that simply clasp the organic potency. This is why I use a completely different line for my lighting. Yes, that mesmerizing ambient lighting that is the source of such a pleasant atmospheric mood can literary take out an enormous portion of aural pleasure.

And what are the benefits of Entreq ground boxes, that are most easily described (based on my listening notes)? The dynamic impact, focus increase and a better sense of organic flow! All of these performance shift-ups were evident almost instantly. The same goes for the more relaxed sonic performance and natural, less obtrusive pace. But it doesn’t stop there. Due to dealing with the different fractions of a system noise the perception of horizontal and vertical scale is notably prolonged with Entreq boxes. This also translates to the darker shade of black. The music is coming from the more black space, without unwanted fade-in effect. The interaction feels more immediate with a grander emotional impact.  
While Entreq ground boxes introduce a noticeable step up in performance, they do not morph the general system sound. That alone is a rare feature, that is worthy all of the embracing. Yes, there is something fundamental about the changes Olympus Infinity and one Olympus are introduces without self imposing nature. 

So are some of the components not designed properly? Are they missing the proper grounding? Are the internal grounding (chassis etc.) not properly implemented and executed? Well, this is not exactly an easy question to contemplate upon. It’s a complex subject matter. If we take in consideration, that some out-of-the-box audio designers will ground each separate panel of the component chassis before even moving to the rest of the innards, this certainly opens up a lot of topics to debate. 
While I have my own in-house grounding system at my reference room this particular approach of  grounding delivers the results that are far more unpredictable and of not such notable difference compared to the level of the impact that I’ve experienced so far with Entreq wooden boxes. Of course nothing can be taken as rule of proof as each high-end audio system is an entity of its own and it’s really not that easy to predict what exactly will happen outside of the known territory, but this should you should offer some insight and the general idea about the benefits and positive boost in the performance. 
The particular setup that is working particularly well combines the Olympus Minimus and the MSB Technology Select DAC (and separately with Totaldac d1-driver) while the two Olympus Infinitiy boxes are connected to the negative binding posts of the Raidho D4.1 speakers. In this combo the Entreq Olympus Minimus introduces a more vivid spacious delicacy. There is also a notch better lower register foundation and the sense of music’s energy transfer is  of much higher density. Similar boost was noted with the double Entreq Olympus Infinity grounding boxes. There is the additional gain with the sense of spectral shading as well as more vivid projection of the acoustical space. 

Playing around with multiple insertions do bring out one question… How many ground boxes will be sufficient? Or better to say, at what stage enough is enough? I’m not sure I have an exact answer, but from what I’ve seen or learned about the grounding, some people really push the grounding implementation to the mind-boggling extremes. Where the sky is the limit, the mortals usually have to settle with an allowed portion of heavenly nectar.

For sure the different complexity of the systems might require alternate grounding applications. At the end of the day, the implementation will be based on the proprietor will and financial ability to explore what seems to be an endless grounding universe. Yet, compared to some other high-end audio accessories, the bang for the buck with Entreq grounding devices is much more wallet friendly then some utterly costly accessories alternatives and once the positive performance distinction is noted, it’s hard to go back to the usual norms.

The aesthetics, sonic advantages and even the smell (natural wax coating), they all clearly follows Per-Olof appreciation of nature, natural materials, and natural laws interactions. I think this is exactly what resembles the official Entreq slogan; “The sound of nature”.  
Yes! As you could decipher, so far I’m really liking the Olympus Infinity and one Olympus Minimus impact. Do stay tuned for part two where I’ll focus on the particular qualities with the reference music tracks. 
Matej Isak  


  • Olympus Minimus Ground Box – 2020 EUR
  • Entreq Olympus Infinity – 3.300 EUR


  • Weight 9 Kg  W 22cm – H 14cm – D 25cm
  • Like with other ground boxes Olympus Minimus it is made of Oak but with the Olympus Infinity you can also be order it in a dark Oak finish. 


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