Soltanus Acoustics Euridiche

What you are about to read is only a part of a bigger article. This part only covers the critical evaluation of the Euridiche. If you are interested in the history behind the company, the founder, and the Euridiche (how it was born and created), then you can read my "Soltanus Acoustics — The Full Story" article here:
https://www.head-fi.org/threads/soltanus-acoustics-euridiche-%E2%80%94-the-full-story.962997/

Author's Note​

In memory of my dear aunt & grandfather, who passed away this month, in April.​

Like the majority of my work, this article was not written overnight. It took a great amount of effort, energy, and patience. Well over 300 hours has been invested into this article. This includes: listening time, composing the article, formatting, taking the photography & editing it, audio interview and transcription of the same one, email exchanges, and general research. The article was set to be published in February/March last year, but due to unexpected delays, it had to be delayed by 12 months.

"Soltanus Acoustics — The Full Story" is 27 pages/13,450 words long. For this reason, as its author, I suggest you read it in chapters, with pauses in between each chapter.​

Disclaimer: The Euridiche was provided to me free of charge for the purpose of writing a review. I am not affiliated with Soltanus Acoustics in any way, nor am I gaining any financial benefit from writing this article. The article is strictly based on my experience and opinion, it is free of any bias from an external force (online influence, other people’s opinion, or the manufacturer itself). The article in itself was fully my idea and was not a requirement from the manufacturer.

Click to expand...

Chapter 4 | Critical Evaluation

Unboxing Experience

When you are in the premium headphone market, you expect premium presentation and packaging. To some people, it’s of more significance than others. In the case of Soltanus Acoustics, you definitely get a premium treatment when it comes to packaging.

The Euridiche comes in a 29.4 cm × 28.5 cm × 28.5 cm (L x W x H) wooden box. On either side of the box, you have what’s called a toggle latch. This latch uses tension to keep the box closed and secured, you can find a similar mechanism on some beer bottles (often called a swing-top bottle). If you wish to lock the latch, there is a hole in which you can stick a pin that prevents it from opening.

The box itself features a military-like paint print. “Soltanus” is on the front side, while “Acoustics” is on the top side. For portability and moving around, there is a well-made rubber handle on top. It is secured with the help of two matte-black metal pieces that are screwed in place. The same metal pieces have “teeth” that bite down on the wood.

Once you open the box, you will discover that it’s separated into two departments:

1) The energizer/amplifier department

2) The headphone department

The latter has two more compartments that are created with wood separators. You can store your cable, extra ear-pads, or similar accessories in them. Both the headphone and energizer are secured in place with firm foam blocks. The cover of the box also has foam blocks that prevent the energizer from moving around, while also protecting both devices from scratches.

While the unboxing presentation won’t blow you away, I think that the packaging is very well-made both looks and feels premium. I am happy to see that no plastic was used, which remains the whole sustainable ideology that Soltanus Acoustics is going for.



Technology & Design

You’re probably looking at the Euridiche and thinking to yourself “Hmm, that looks familiar”, and you’re not wrong. It heavily resembles Audeze’s flagship LCD-4 and it’s not trying to hide it. Both the headband design and system remain almost identical. The rod headband system offers 7 height adjustment steps and roughly 45˚ of swivel (horizontal rotation).

Unlike the early wooden version of the Euridiche, the current one has circular ear-cups. Besides the Soltanus Acoustics logo by the headband, the ear-cups’ faceplate features “soltanus acoustics” typeface on the upper end and “Euridiche” on the bottom end in a cursive font. Speaking of the faceplate, it is held down with the help of 8 hex screws. However, it’s a little bit more complex than that. The ear-pads themselves feature a firm and sturdy base that has 8 holes, and the faceplate is screwed into that base. Because this is a rather unusual design, it means that you cannot just swap out the pads with any aftermarket ones. This sandwich design allows both the faceplate and the ear-cups to be pressed hard against the housing, and this should mean that there is a tight seal. It is basically a sandwich design. The faceplate on its own features a honeycomb design for airflow.



But let’s get to the most interesting part about this headphone... The technology.

Among the first things that you will see are the 3-step toggle switches that are located behind the tube-like headphone connector housings. I knew that some people would question what this toggle switch does and how it works, so I went ahead and asked Zoltán some technical questions about it.

As it is explained on Soltanus Acoustics’ website and in the user manual, this is a tuning switch. Before I go ahead and explain how it works, I need to explain what the electrostatic driver setup inside this headphone looks like.

Electrostatic drivers are divided into two categories: flat, conductive sheets (Sennheiser, HiFiMan, Warwick Acoustics, Kaldas Research, ES Lab, Stax, Koss) and stretched wires (Soltanus Acoustics). Now, in the loudspeaker world, there are several companies using either of these stators, but in the headphone world, Soltanus Acoustics appears to be the sole company using stretched wire stators. An electrostatic driver works by placing a static electric charge on a film (membrane) that floats between two stators. Zoltán took the stator design from loudspeakers (his own Virtuoso) and applied it to his Euridiche headphones. Once you take off the faceplate and the ear-pads, you will find two stators (four in total). Each stator consists of 21 vertically placed copper wires (rods). Unlike flat, conductive sheet stators, stretched wire stators allow you to electrically separate them. Now that you have a basic understanding of electrostatic stators inside, I can go on to explain how the tuning switch works and how it takes advantage of this design.





As Zoltán explained, the first 8 rods from the front are always directly connected to the full signal, i.e., they receive the full frequency range (low, mid, high), while the remaining 13 are connected through the tuning switch (electrically separated). The switch allows you to gradually decrease the high frequencies (>1 kHz) by 2 dB. The Euridiche has three tuning modes/steps:

1. Outwards (full-frequency) — All 21 rods are receiving the full-frequency spectrum

2. Middle (2 dB decrease in high frequencies) — The affected 13 rods have a 2 dB decrease in high frequencies.

3. Inwards (4 dB decrease in high frequencies) — The affected 13 rods have a 4 dB decrease in high frequencies.

Besides the decrease in upper frequencies, this also moves the sound image forward. You have to remember that the first 8 stators are always receiving the full signal, so if you are decreasing the high frequencies on the 13 stators, the sound image will gradually move forward as you change modes.

Personally, I couldn’t hear a huge difference in sound. As far as being an audible difference, I heard that position 1 (full-frequency) is brighter and has more sparkle than position 3 (4 dB decrease in high frequencies), but I couldn’t hear a difference between 1 and 2, and 2 and 3.

I would also like to go back to the stators because there is more to cover. As mentioned before, Zoltán made 20 different stators until he settled on the rod type. He explained his reasoning as to why he stays away from conductive sheets:

“The holes that are present on perforated conductive sheets have a resonance. The little holes act as a small resonator. The perforated holes are actually tubes because you have the thickness of that plate and you have the diameter of the hole, within that hole you have a mass of air. That mass of air and the resistance to airflow create a resonant circuit that affects high frequencies. In my rod stators, you do not have such a problem because sound travels much easier through it.”

I also mentioned earlier that Soltanus Acoustics is the only company that uses such stators in headphones and there might be a very prominent reason behind it. These types of stators require a lot of labor, as opposed to perforated conductive sheets that can be made with a CNC machine. The rod stators require straightening, cutting down to size, soldering, gluing, putting them in place on the mold, etc. This type of work cannot be done for mass production, which might be another reason why we haven’t seen it in this space.



Build Quality

Moving onto the construction aspect, let’s start from the top to the bottom.

The headband is made of carbon fiber just like the Audeze ones. I found out that it’s made by a local company that specializes in manufacturing sports tricycles. The main piece of the headband (the part that holds together the whole headband construction) has a plastic housing and anodized aluminum plates. When you are looking at it from the top view, you can see that it has a hole that allows the yoke rods to run through it. Speaking of the yoke rods, they are made of metal, while the headphone yoke and the headphone faceplate are made of anodized aluminum.

I went over how the early versions were made of wood, so I’d like to cover the story of how we got to the material that is used in today’s pairs.

Zoltán switched to 3D printing technology only a year after making the first wooden Euridiche model. Considering that he made the wooden pair exclusively for Dr. Rudolf Klein, and not as a public release, this was a pretty major step to make. He saw the future in 3D technology, and he went on to mention all the benefits:

“This is the most modern technology that you can buy as of now. You do not have material waste, you don’t waste any material, and you don’t have to stand by the printer […] It uses very little energy. Sure, it is not for mass production, but that’s not something that I want to do with my products anyway. This technology is perfect for my needs.”

He also owns a CNC machine, but explained why he doesn’t use it:

“The first reason is that I do not have to control and stand by the machine all the time. The second is because 3D printing technology allows me to make shapes and pieces that are impossible to make on a CNC machine. I am able to make very fine shapes on the 3D printer that would be otherwise very, very hard to make on a CNC machine, but also, I would never be able to make inside-hollowed pieces with a CNC machine. And the third is that I am not littering or polluting the environment. I am using such materials that when they are thrown away, they degrade […] It is a special 3D printing material, it’s more expensive than others, but it is a very good and sturdy material.”

That just about covers the construction and materials used on these headphones, but what about the inside? The stators are made of factory lacquered pure copper. The lacquer layer acts as insulation, which is essential for an electrostatic driver. The rods that Zoltán is using feature two layers of fabric lacquer. Without this insulation layer, there would be a dielectric breakdown and due to the high-voltage present, sparking would occur. On the inside of this headphone, you have the already described stators, but there’s also the membrane which I haven’t covered. This membrane is made of 2 μm (micron) thin Mylar foil that is placed between two fiberglass pieces. To put this thickness in perspective, human hair is ~70–180 microns thick. The membrane has a nanocrystalline graphene coat on it that allows the driver to function in a push-pull design. The said fiberglass is a total of 1 mm in thickness (2x 0.5 mm). The Mylar is glued to the fiberglass with special elastic glue.

The membrane is 104 mm in diameter, making it the largest on the market—at least from what I could find.

“When they invented Mylar, somewhere around in the ’60s, they drove a Volvo car on the foil itself, they wrapped the Mylar around the car like a bag, and they tied it in a knot to a crane. When they lifted the Volvo car, everybody dropped on their bums and wondered how such foil can lift a car that weighs a tonne and a half.” Zoltán explained the strength of Mylar foil. As I had done my homework and research, I found that Mylar was actually invented in the early ’50s. I also found out that the car that they lifted actually weighed 3 tonnes! You can actually take a look at the original photograph of this very event here: https://digital.hagley.org/AVD_2004268_P00002245

Euridiche is a flagship headphone, and something that stands out is the fact that the membrane is easily replaceable, just like every part of this headphone.

“The only part that can degrade (after 10, 20, 30 years) in my headphones is the membrane. That’s why it is replaceable. This is an innovation, up until now, nobody featured a membrane that you can replace by yourself.”

I would agree with this statement. Kaldas Research is the only other company that offers a replaceable membrane. This is a crucial feature that allows a product to theoretically last a lifetime.



Cable

One thing I want to get straight out of the way is that the current (March/2022) photographs on the Soltanus Acoustics website are outdated. The Euridiche no longer comes with a flat wire cable. The Euridiche series now comes with a premium custom-made cable.

It consists of a high-purity (99 999%) mixture of copper and silver. The copper and silver are sourced from England. Instead of the standard stranded wire, Zoltán went the solid-core way and this was not by accident:

“Based on our findings, solid-core sounded better. Soltanus Acoustics cables have a lot of wires of varying thicknesses (0.15–0.45 mm). It is very important that everything is individually insulated, that not all the wires are in single insulation.”

The cable on the Euridiche is a 9-core cable, and every wire is individually insulated with a Teflon sleeve. It should be noted that this very cable used to be manufactured by Dr. Rudolf Klein, who is the original designer. However, Zoltán took over the responsibility, and now he makes the cables himself.

When I asked whether the cable has shielding, Zoltán had this to say:

“It is not shielded. It’s not needed for headphones. If it were shielded, it would create a capacitance that would have a negative effect. If the cable were shielded, it would have a greater capacitance than the headphones themselves.”

That’s what’s going on on the inside, but on the outside, you have a cotton sleeve that wraps all of the Teflon-insulated wires. The whole cable itself is quite rigid, and you can’t straighten out any hard curves that are present. It makes it a good cable if you are sitting in a chair and the amplifier is in front of you. However, if the cable has to bend and curve, you might find yourself fighting with the cable. What’s also worthy of mentioning is that Zoltán recently introduced the option of choosing between 3-pin XLR connectors and a STAX Pro Bias 5-pin connector. If you choose the 3-pin XLR option, you will have two separate strands of cable that each end in 3-pin XLR. So far, I believe that Zoltán’s amplifiers are the only ones that support the dual 3-pin electrostatic XLR connection. If you prefer, you can also make a cable yourself or buy one because the Euridiche has 3-pin mini-XLR connectors on the headphone end. For example, I had no issues using the cable that was supplied with the Kaldas Research RR1.




Comfort

Weighing in at 620 grams, it sits at the far end of the weight spectrum. Yes, there is the HEDDphone which sits in at 700 grams, and then there are some Audeze headphones that weigh over 700 grams, but 620 grams certainly falls under that “heavy-heavy” headphone weight category.

Despite its weight, it’s surprisingly comfortable. This is all thanks to the oversized ear-cups and the highly flexible ear-cups. Zoltán went through a number of ear-pad variations, of which I had a chance to experience three: very hard ones, semi-hard ones, and softer ones. The very hard ones were the first iteration and weren’t comfortable. The semi-hard ones are pretty good and they are the ones I spent the most time with. The softer ones are also pretty nice, but since the clamping force isn’t all that strong, the difference is barely noticeable. I suggested the use of memory foam, but it turned out that the ear-pads fully compressed and thus negatively impacted the sound performance. At the end of the day, everything was figured out and a somewhat perfect balance has been found. The ear-pads are very thick, measuring around 3.2 cm. They also have a fairly large surface area, measuring around 2.1 cm. My ears had no issues with the inner size of the ear-pads. The inner diameter measures 7 centimeters. It’s the combination of all three of these factors that makes the seal good.

I’d say that within the first hour or two, everything is completely fine. However, after that period of time, I experienced some physical fatigue. Though obvious, I do think it’s important to state that the majority of that fatigue formed on my head, that is, from the weight on the headband. If it weren’t for such an open-back design, I am almost certain that the fatigue would’ve occurred much earlier.

I wouldn’t exactly say that the Euridiche is a headphone you’d be walking around with or banging your head like a maniac to... The best-case scenario would be sitting in a comfy lounge chair that supports your neck/head. It’s really important that you rest your neck against something soft.

Sound Performance​

Lows

Among my first speculations about Euridiche’s sound performance was its delicate yet deep bass performance. Why “delicate”? Well, I believe that the lower frequency range isn’t particularly pronounced, especially not like it is in many headphones. It’s not overwhelming. There is a sense of balance, a focus on the quality of bass instead of quantity. Sure thing, I appreciate a great lower extension, but I also appreciate an overall balanced sound signature—something that I also came across in the Ollo S4X.

I sometimes experience ear fatigue when a headphone has a too overwhelming low-frequency response. This is not the case here. The bass has the depth of the body but in a very subtle way. As far as words can go, I think that no word describes it better than “soft” and “delicate”. Again, for clarification purposes, do not misinterpret these two terms, because Euridiche is more than capable when it comes to its bass quality and quantity capabilities.

Perhaps “Theme for The Irishmen” by Robbie Robertson surprised me the most. As soon as you play this track, you are met with a drum and percussion with long decay. The parts that completely blew me away occur at the 1:03 and 1:04 minute marks. At these parts, the drum is panned to the left, and it sounds so realistic, so true that it doesn’t even feel like I’m listening to a headphone. This is more related to imaging, but I simply had to state it. Where you can really hear the sub-frequency capability of this headphone is at the 1:46 and 3:58 minute marks. What’s in question is a growl and tone coming off a cello. It is a very deep tone that you feel, proving Euridiche’s ability to dig deep and break away from the stereotype that electrostats are incapable of producing strong sub-tones.

“Why so Serious?” by Hans Zimmer, a standard test track of mine, is a perfect example of the deepest sub-frequencies present in the music. Though subtle, at 3:26 the climax is reached and the drop occurs. What I am able to feel rather than hear are the very deep frequencies. They have quite a lot of weight and truly feel heavy, but are barely audible—which is how this part is supposed to sound. Michael Jackson’s “Smooth Criminal” is another special testing track of mine. I listen to the “heartbeats” in the introduction. In this track too, this headphone was able to produce a clean sub-bass tone. Each heartbeat is felt, it sounds like a strong “thud”. Another example of Euridiche’s sub-bass capability can be heard in Angel Olsen’s “Spring”, where there is a sub-bass undertone present in the bassline.

Even “Do I Wanna Know?” by Arctic Monkey has the said depth quality. I always this track as a bonus, it serves as icing on the cake track. If the headphone performs well in the lower region in this song, I know that it is doing something special. The introduction (0:00—0:04) features a thumping drum. It usually sounds too boomy, too thin/flat, or sounds just right. With these headphones, you can hear both the “oomph” and the decay. At around 0:05 you can hear the even deeper tones that are coming off the bass guitar. Although this is a very well-known track, it’s not a track that gets carried out well by most headphones. I was pleasantly surprised by Euridiche’s performance here, because, as I said, headphones rarely are able to pull this one-off.

The Euridiche also bears very well in terms of mid-bass qualities (impact, punch, speed). This kind of goes back to what I said in the beginning, that the focus is on the bass qualities. In terms of speed, much like the high-frequency response, both the attack and the decay are responsive and fast. This is the reason why I found the bass to be snappy. Besides my standard speed test tracks (MOON — “Hydrogen”, Lee Curtiss—Smoking Mirrors), I really found the same snappy quality in both the usual percussion drums and in electronic music. Whether it was Deadmau5, Burial, Massive Attack, Daft Punk, rave, hip-hop, or just rock, the low-end always had a fast attack & decay, fast delivery, and strong impact. “Bulletproof Soul” by Sade is a perfect example of bass depth, speed, and presence, and it’s another one of those tracks where Euridiche doesn’t disappoint. In Fleetwood Mac’s “Oh Daddy”, the kick drum (if I am not mistaken) has a very mature “thud” quality.

During my visit to Zoltán, I also brought my iBasso SR2 and Ollo Audio S4X headphones. This is something I didn’t initially mention, but this is the perfect segment to reveal it. When Zoltán listened to both headphones, he was amazed and pleasantly surprised by how neutral the S4X sounded, and it was also the headphone he liked more. On the other hand, I definitely preferred the SR2 for music listening. Then, a while later, I had a friend visit me. Something that you should know about him is that he has a pair of Megnepans and they are his primary speakers, the speakers he is used to hearing. When he listened to the S4X, he had a very similar reaction as Zoltán. He liked them very much, he liked the balanced sound signature, and he also preferred them over the SR2. What I could conclude is that both of them were used to flat-panel speakers (without subwoofers), so they are used to that more balanced sound signature where you do not have a big emphasis on the lower frequencies. I think that the Euridiche offers similar performance in a headphone form factor. Imagine the Euridiche as a pair of Magnepans with good subwoofers.



Mids

Anyone who has been reading my previous work is aware of my admiration of strings. With this being said, I’d like to start off by talking about strings.

The Alan Parsons Project— Some Other Time
Led Zeppelin – Babe I’m Gonna Leave You
Dire Straits – Private Investigations
Fleetwood Mac – Go Insane - Live 1997
Fleetwood Mac – Oh Daddy
Joan Baez – Diamonds and Rust
Joan Baez – Song of Bangladesh
Deep Purple – Soldier of Fortune

Strumming or plucking of a guitar (usually either classical or acoustic) is present in all of these tracks. That is the element that you should listen to.

Ugh… Just listening to strings, it’s hard to pull myself away from them and type. I mean, how can you distract yourself from such pleasure?

Euridiche is a dream when it comes to strings. To keep it short and sweet: it has the bottom end that defines a string pluck, it has the mid-range tonality that makes a string sound like a string (timbre), and it has the upper end that is another very, very important aspect when it comes to making a string sound like a string. This is a very vague description, but each element consists of its own set of complex details and qualities. It depends from guitar to guitar, from recording to recording, but I personally most enjoy guitar plucks that are felt. And for a guitar pluck to be felt, the headphone must have a good lower mid-range response. It must have fast attack and a responsive decay (if you think of the sound of a guitar pluck, it is very snappy at the beginning, and has a soft, but long-lasting decay). However, there are also guitar plucks that possess both fast attack and short delay, resulting in a “dry”, metal-like sound. The one I described before could be related to the sound of a guitar with reverb. I’m no music/instrument expert in any sort of way but think of it like the sustain pedal on a piano.

“Some Other Time”, “Babe I’m Gonna Leave You”, “Go Insane” fall in the first category: more “dry” strings.

“Private Investigations”, “Oh Daddy” (though at several parts the guitar sounds very tight and tense), “Diamonds And Rust”, “Song of Bangladesh”, “Soldier of Fortune” fall in the latter category: guitar plucks have more reverb/sustain.

As for vocals, I think it’s quite a love it or hate it situation. You are either going to fall in love or you are going to be unsatisfied. This is especially the case if you listen to a lot of “old” rock because that’s where you notice the raw nature of vocals the most. I use the word “raw” to describe the quality of vocals due to the lack of another word that accurately describes how vocals sound. Usually, vocals sound pretty full and not lifelike on headphones, and this is done with a purpose. It sounds better, especially for the masses. It’s easier on the ears, which is something I noticed more people lean towards. However, on the Euridiche, vocals really sound lifelike, they sound like there is a person actually singing, instead of it sounding like you are listening to a person singing on headphones. Keeping this in mind, it’s also worth mentioning that vocals sound more aggressive. When you come across a track where the singer really opens up their voice, you can both hear it and feel it— the same way you’d experience it in person. “Transparent” would also be a word that describes this sonic quality. There is no indication that the sound is being altered, it feels “raw” and “transparent”.



Highs

The most prominent feature of this headphone, by far—in my humble opinion—is its upper-frequency response. That is, if we are only taking into consideration the frequency response. I am a sparkle junkie, and my, oh my, have the sparkle gods spoken. I don’t know about everyone else, but I find sparkle the very element which gives life, excitement, and energy to music. You can have head-shaking bass, crystal clear highs, but if that treble doesn’t tingle your ears, damn does it feel empty. I won’t say that the combination of a very good mid-range and a very good low end doesn’t sound good, but I will say that after a certain period of time I always find myself looking for that sparkle.

At this point, I know that I am a lover of a good bright headphone. I’ve probably said this a dozen times, but I will repeat: bright ≠ piercing, sibilant.

Unfortunately, due to false stereotypes, the “bright” sound signature has gotten a bad name. Bright is a good quality, but due to the common bogus belief, it is associated with bad qualities. To cleanse the word “bright”, let’s break down what are good and what are bad treble qualities.

Good: sheen, sparkle

Bad: piercingness, sibilance

Here’s an excerpt from my iBasso SR2 review: ”

1) Shine is a sound characteristic of a good amount of clarity and detail retrieval. In this case, a headphone with no shine would be a warm headphone.

2) Sparkle is a sound characteristic of a greater amount of clarity and detail retrieval than shine - it is a very hard characteristic to pull off because oftentimes it’s easy to cross the line and go into sibilance. When done correctly, you experience a very satisfying “tingle” feeling in your ear.

3) Sibilance is a sound characteristic of “extreme” clarity and detail retrieval, i.e., the most revealing. This is a known characteristic of an analytical sound signature, and one of its drawbacks is that it easily becomes fatiguing, making it a not so ideal option for long listening sessions.”

But wait, how can sibilance be a bad quality if it’s a sonic characteristic of an analytical sound signature? Well, it all depends on what area it is in. In the professional audio field, sibilance is common. From speakers monitors to studio headphones, it’s common to find professional audio listening equipment unenjoyable for music listening. The field of application severely matters! When it comes to music listening, sibilance should be seen as a negative quality, while in the professional field it is seen as a positive quality. However, to make matters even more complicated and unclear, as it is often said, it’s all subjective.

What one finds piercing and sibilant, the other finds “enjoyable”. That’s the subjective factor.

To conclude this little rant: if a headphone is unpleasant due to its treble response, it is not bright. It is either sibilant or piercing. This concluding statement overlooks any objectivism because we are strictly talking about one’s experience that is related to their emotional interpretation of music/sound. e.g., it doesn’t matter how aggressive a person likes the treble response to be, the point from which it becomes unpleasant should be called and considered piercing or sibilant. Hope that makes sense.

The biggest downside of this is that you must know the person’s taste in order to fully understand what is piercing for them.

From albums such as Daft Punk’s highly acclaimed “Discovery” to Kendrick Lamar’s “DAMN.” and “good kid, m.A.A.d. city”, from The Alan Parsons Project’s “I Robot” to Russian Circles’ Geneva, from Roger Waters’ “The Pros And Cons Of Hitch Hiking” to Yes’s “Drama”… you get the point, I can go on and on forever. You simply cannot overlook the bright nature of the treble. It’s a highly resolving headphone—in fact, the most resolving I’ve heard—and that’s something that you either like or dislike.

When I first had a chance to listen to the Euridiche, I kept coming back to it. And while many factors attracted me so much, I think that it was primarily the treble response that had me so curious about it. Excuse the vulgarity, but it takes some balls to pull this off the same way that Soltanus Acoustics did.



Soundstage, Imaging & Separation

This is the selling point of these headphones. It is simply too good in all three of these. Way too good. "Exceptional" wouldn’t even be close to describing how good it is. However, you know what would? To say the following:

This doesn’t sound like a headphone.

It’s the most precise, accurate, and grandest-sounding headphone I’ve heard. Unfortunately, I haven’t had a chance to listen to other TOTL headphones, so I can’t say how it compares to them. I can, for example, refer to some physical qualities such as that the soundstage is wider than my arm span. For more context, the distance between the outside of Euridiche’s ear-cup and the tip of my fingers is roughly 86 cm.

The soundstage width isn’t what makes this the most spacious and open-sounding headphone I’ve heard. The full credit for that goes to the other two qualities: imaging and separation. I can firmly and confidently say that the Euridiche possesses hyper-realistic imaging & separation qualities. To me, hyper-realism (in sound) refers to something that doesn’t sound like it’s coming from a speaker/headphone anymore but sounds fully lifelike. I guess you can say “realistic”, but I think that that term has gotten a completely different meaning. When I say “hyper-realistic”, I am essentially saying that the listening experience through these headphones is like the real-life listening experience through our ears. More often than not (I’d personally say 99%), headphones sound like headphones. They can possess realistic qualities, but at the end of the day, it still feels like you are listening to headphones. On the other hand, the listening experience on the Euridiche is everything but headphone-like. I would go as far as saying it’s lifelike.

You know how an artist holds a microphone when they are performing live? Well, with the Euridiche you are in the position of that microphone. Note how I didn’t say that it sounds like you are the microphone. Though, I will say that I don’t think we will ever have a headphone that can compare to the real “experience” of a live concert — especially an outdoor live concert. Even trying to put you in the position of the performer, I don’t think any headphone will ever be able to present the sheer size and feel of a live concert. Also, I put experience in quotation marks because I am not referring to the personal experience, but rather to the physical sensation/experience of a live concert. Live performances aside, I’d say that Euridiche’s capability to paint a lifelike image is unmatchable. This is a very bold statement, especially coming from someone who didn’t listen to other flagships. Depending on the recording, you can fully picture the room that the track was recorded in, and that’s what inspired me to say what I just said.

The thing with the Euridiche is that it’s fully transparent. To clear any confusion, I am talking about its physical behavior (isolation & sound leakage). It doesn’t block any noise. It neither blocks sound coming in nor sound coming out. For this reason, I am challenged calling it a headphone. I think that it’s much more appropriate to consider it an ear-speaker because that’s exactly what it is. This is the most sensitive headphone to its surroundings I’ve heard. Just placing my hand ~30 cm away from an ear-cup, I could hear that it affects the sound. Though this is a quality that allows it to have such an open sound, it’s a con if you don’t listen to your headphones in a space where there is nothing nearby, aka an open space.

I’m not even sure whether I can do an analytical evaluation because these three qualities are truly present and audible in just about every track.

Of course, for the soundstage, you have Yosi Horikawa’s “Bubbles”, which sounds surreal, but it is a binaural recording, which is cheating in a way. While I did hear elements in that track extending around or beyond my extended arm (86 cm), I also heard the same quality in other tracks which weren’t binaural recordings. Unfortunately, because I spent so much time listening to different tracks, I truly cannot recall the exact tracks in which this insane soundstage width was present. Listening to music with these headphones is like listening to it for the first time. You are able to hear things you’ve never heard before. All of a sudden, you start observing all those things. “Oh, so this violin is placed upwards”, “this guitar is placed farther back, to the bottom”, “this cymbal is placed forward, to the left”. You get this very large 3D platform, and you can analyze and hear every element in that 3D space.

For imaging, you have Pink Floyd’s “Dogs”, which is another track that I swear by. In fact, I think “Dogs” was one of the earliest tracks where I truly noticed how precise the imaging is. Another track that I remember is Rare Bird’s “As Your Mind Flies”. As I was exploring different albums, I came across Symphony from Rare Bird, and there are a bunch of great tracks on it, but “As Your Mind Flies” in particular stood out to me due to the panning of the drums.

For separation, I clearly remember Sia’s “Dressed in Black” just completely blowing me away. At first, the track sounds pretty standard, then some drums kick in, and bam, an explosion of elements happens and all of a sudden it’s pretty crowded. This so-called explosion occurs three times: at 0:55, 2:23, 3:33 minute marks. Each time it’s slightly different, with the last one being the most different because it extends to the end of the track (6:40). On the Euridiche, all the elements are crystal clear and possess exceptional definition. However, the most fascinating thing I found is how easily you can separate out the different vocal tracks. In the first two “explosions”, there are two vocal tracks: the primary one and the secondary/background vocals. In the third one, there are three vocal tracks. Now, the interesting thing is how well you can separate out these vocal tracks. If you wanted to, with the help of focus, you could completely isolate and focus on the background tracks and “bring” them to the foreground. This is something that I haven’t heard on other headphones. Yes, you can hear the different vocal tracks, but they are not as well-defined and as clear as they are on the Euridiche. I could also put it as though the background vocal tracks are voices of their own — it’s not as though they are overridden by the primary vocals, they sit in a space of their own.

The conclusion I came to is rather logical, but a conclusion nonetheless. The Euridiche’s soundstage, imaging, and separation capability are the most audible when the mixing and mastering engineers did their job right. How can you know if they did their job right? That’s a good question! I guess the answer would be subjective because it depends on what their goal was, but I will say that when the mixing and mastering engineers put in the effort to separate each element in the mix, Euridiche picks it up in an exceptional fashion. Engineers can spend countless hours putting together a complex mix, only for it to be listened to on stock earphones that come with your phone. Every layer, every position, every element, everything is crystal clear. You can hear everything.

To be fully honest I’ve tried doing an analytical evaluation numerous times. What happened every time is that I’d listen to a song or an album, then I’d go to the next, I’d make pretty solid observations, but I wouldn’t write them down. I always went “one more, just one more”… the next thing I know is that I spent 10 hours listening to music and haven’t written down a single thing. I am not even exaggerating. Let’s just say that it’s easy to get carried away by music. As it should be!

Bonus | Outstanding Performance

If there is a single album that has all sound qualities present, it's Sérgio Mendes' "Brasileiro". A severely underrated and largely unknown album, but without doubt, one of the greatest engineered albums I've listened to. I would be a liar if I told you this album is anywhere close to my preference in terms of taste and genre, but what I can appreciate and praise about it is how well put together it is. While it's a mostly unrecognized album these days, back in 1993 it got the deserved critical praise and approval. Brasileiro won the second-ever "Grammy Award for Best Global Music Album" and the engineer—Moogie Canazio—was nominated for the "Grammy Award for Best Engineered Album, Non-Classical", but lost to Michael Jackson's "Dangerous". There is a reason why some refer to Brasileiro as "the Bible of engineering". It's a true masterpiece, an engineering masterpiece. Sérgio Mendes probably wouldn't be so happy if he found out that I only play his album to listen to its technical qualities. If you never listened to it, please give it a play. I promise you will not regret it! It's a ride you don't want to miss, especially because it's such a unique experience. It's also very fun to explore your headphones with it, see how much they blow you away. This is pretty much the summary of the 54:41 minutes:

Conclusion​

I know that many people in this hobby never get fulfilled. It's almost as though they are chasing something, that craving that needs to be satisfied… but they never catch it and that craving never gets satisfied. With the Euridiche, I feel like this is the tip of the mountain, I don’t have that need to search for something more. I can certainly picture this headphone as the endgame for many. With dozens of headphone models getting released every year, I am left scratching my head wondering how nobody found out about this gem. It makes no sense. If it was an entry-level product, then sure, it’s easy to overlook such a product in such a saturated market. However, this is a flagship product, and for a flagship product to remain anonymous for two full years… it’s a first for me. I’ve never seen it happen.

A great number of you that have made it to this point most likely would’ve never imagined that such an unknown product could have such a rich story, but hey, this is what I love about being an author. Aside from critical evaluation, I love storytelling. While it’s not the case here, usually a product has a whole team of people behind it, and each person from that team holds a story. I believe that critical evaluation is just a small part of a product, but perhaps the most important to someone purchasing it. It’s important, I won’t debate that, but not enough attention is paid to the people who made that product come to life.

With virtually no previous experience in the headphone field, Zoltán Mikovity successfully made a masterpiece. Not only is it a masterpiece, but it also puts the “electrostats have no bass” stereotype in the bin. The best part of it all? It happened by accident. It was never in his plan to create a headphone.

That’s my favorite part of the story.

The price to performance ratio is not to be questioned. It's a top-of-the-line headphone, and it performs like one. I could talk about its sound performance for eternity. Putting the whole experience into words isn’t exactly easy. The Euridiche puts you in the booth with the artist like no other headphone. Instead of it feeling like you are listening to music through a headphone, it feels like you are in the music. It’s not a headphone listening experience, it’s far from it. If you were to ask me to describe the Euridiche in two words, they would be: raw and real.

Vocals sound human, they have the dynamics and the energy that a human voice has in real life. Instruments have the timbre and aren’t static. Simply said, everything sounds alive.

It doesn’t sound digital, it doesn’t sound analog, it sounds real.

Chapter 5 | The Setup

Amplifier: Soltanus Acoustics Fortissimo







DAC: EarMen TR-Amp…

Unfortunately, due to Fortissimo’s lack of balanced inputs, I couldn’t use my iBasso DX300 MAX as the DAC, which was something that I really wanted to do. You can look at this as the only weak part of the chain. With this being said, you can only imagine how good this headphone can sound with a proper TOTL DAC if it blew me away with an entry-level one.

Cables & Accessories




First of all, let me get this clear: I was never and will never be the person who will say that cables do or do not significantly alter the sound. There are a lot of different people in this hobby, but you can generally divide it into those who are equipment first and those who are music first. I fall in the latter category. Now, don’t get me wrong, I fully understand the first group, it’s just that I am not a part of it. I understand those who are highly passionate about technology & equipment, I understand going to extremes for the slightest differences. You can be enthusiastic about either music or gear or can be enthusiastic about both. That’s why you can’t exactly fit everyone in two vague categories. I myself find AB testing something such as a cable highly exhausting, both emotionally and physically. It makes me hate the process of listening to music, hence why I avoid doing it. This is also the reason why I neither deny nor embrace that something like a cable can alter the sonic performance. To me, it is unimaginable to sit down and listen to a cable. To give you a clearer image of what this feels like, imagine putting a claustrophobic person in a coffin. This brings me to a rather harsh quote from Alan Parsons on audiophiles:

“Audiophiles don't use their equipment to listen to your music. Audiophiles use your music to listen to their equipment”

However, when it comes to cables I know that you buy them once and will never again… unless you want more cables.

That’s why it is not a bad investment. I also believe it should be among the last purchases you make for your setup. I don’t think anybody should be spending their last penny on a cable, but I do think it’s a choice if you can afford it and it is reasonably priced compared to your setup. I look at it as the icing on the cake. But if you are going to be spending any money on a cable, you want to make sure that the claims make sense and aren’t negatively affecting your listening experience. In other words, you want to make sure that you are paying for quality, not for false claims.

Disclaimer: All the accessories featured below were supplied to me free of charge. I am neither affiliated with ViaBlue nor Lavricables.

Without further ado, here are the cables and accessories that I used:

ViaBlue​

Unsatisfied with the then-market’s cables, Jörg Loidl founded ViaBlue in 2001. The company’s headquarters remain in Malsch, Southern Germany to this day. Mr. Loidl has a professional audio background. After all, he founded the company because he couldn’t find cables for his studio monitors, that is, he couldn’t find cables that had a good enough performance for professional studio use.

The company first caught my eye when I saw one of its now-authentic plugs on some cables. After doing a quick Google search, I found its website. Surprised I was, to say the least. Not only does ViaBlue manufacture cable connectors, but just about everything you can imagine that is related to cables… and beyond. You can buy pre-made cables, but you can also buy individual parts (e.g., sleeves, splitters, ferrite filters, solder & more). This is what fascinated me because usually cable companies keep their components exclusive to their cables. ViaBlue does not do that. Perhaps you want to use their plugs, but want to use your own cables. Mix & match, it’s all possible!

You are not forced into a closed ecosystem where you are limited to buying only cables. You literally have the freedom to use parts that ViaBlue implements into its pre-made cables. There is no sort of hierarchy present. No gatekeeping. It’s as transparent as it gets!

That is just the first aspect that amazed me. I was blown away on a whole different level once the cables arrived and I had a chance to feel them in person. The materials are top-notch quality, and that is quite apparent just by holding one of their cables. They got weight to them! In my eyes, ViaBlue cables possess all three elements that make a high-quality cable: look, feel, quality. Let me elaborate. First of all, they are very appealing. When you see one of their connectors, you immediately know it’s a ViaBlue connector. Secondly, the quality to price ratio present in their cables is insane. Each cable is built like a million bucks. Each cable feels like a million bucks. Each cable looks like a million bucks.

X-60 Power Cable [EU]




This cable uses ViaBlue’s T6s power connectors. These connectors tick all the industry standards and also come with a few premium extras. On the power outlet end, there is a CEE 7/7 Shuko EU plug. Citing to Wikipedia: “The CEE 7/7 plug is a hybrid which includes both side earthing strips, as in CEE 7/4 Schuko, and an earthing socket, as in the CEE 7/6 plug. It can therefore achieve an earth contact with both CEE 7/3 (Schuko) and CEE 7/5 sockets”. On the amp end, there is an IEC C15 plug.

Now, the premium extras. Both plugs feature 24 karat real gold-plated contacts. Also, both plugs are sat in “massive” polycarbonate housings. Last but not least, the housings feature ultragrip coating which makes them scratch-resistant and gives them a satin finish. Due to the polycarbonate material used, the housings are flame-redundant and “break-proof” according to ViaBlue.

Both T6s power connectors use dust-free cable sealing through soft-disc technology and cable fixing by double screw connection (double-screwed strain relief).

The cable itself consists of 3 cores made up of silver-plated OCC copper strands. To achieve “100%” shielding, the cores are surrounded by braided and aluminum foil shields. For the cable sleeve, it uses ViaBlue’s exclusive Cobra braided sleeve.

In addition, the cable features two VIABLUE™ ferrite filters. What exactly is a “ferrite filter”? It consists of a ferrite core which is housed in a satin-matte aluminum shell. The function it serves is “suppressing the amount of high-frequency electromagnetic interference (EMI) noise found in electronic circuits”. Ferrite on its own is a ceramic material of iron oxide and additional metallic elements. All are electrically non-conductive, meaning that they are very good insulators”. The model used on the X-60 cable is the “ferrite filter 18”.

If you are feeling curious, you can unscrew the top part of the ferrite filter just by twisting it with your bare fingers. Once unscrewed, you will actually be able to see the ferrite core.

NF-S1 “Quattro Silver” RCA Cables



This is the company’s entry-level silvered RCA cable. It features ViaBlue’s T6s RCA connectors which are 24 karats real gold-plated. The connectors use a completely closed tubular ground contact for complete insulation and shielding. Two strain relief screws provide a strong hold of the cable. The connectors are sat in satin-matte aluminum housings.

The cable itself consists of two oxygen-free copper (OFC) inner conductors. Each conductor uses polyethylene insulation and is made up of 19 mm × 0.19 mm single strands. It gets the name “Quattro Silver” from the four shields it uses. It features two silvered spiral shields and two ALU-PET foil shields. For the sleeve, it uses ViaBlue’s exclusive Cobra braided sleeve.

The version I have is the Mono version, and it is made up of two individual NF-S1 cables. Each cable features two ferrite filters. The model used on the NF-S1 cable(s) is the “ferrite filter 9”.

Also, do note that the two “wires” on the sides are just fillers to achieve a round shape.

TRI Spikes



The TRI spikes consist of two parts: the base and the upper body. The upper body itself is made up of the body and the spike plate. The spike plate is screwed into the body, and at the same time, this screwable design acts as a height adjustment system. The spikes are screwed into the spike plate. The body and the spike plate are made of coated metal, while the spikes themselves are made of stainless steel. The base is also made of two parts, but they are joined together. The body of the base is made of the same coated metal the upper body is made of, while the inlay of the base is made of stainless steel.

Extra info about ViaBlue

How does the strain relief work?


It's a fastener/clamp that holds the cable so that the strain load does not hang on the solder joint or the strands. In our case, the strain relief on the small connectors consists of the rear screw in the T6s sleeve, which presses on the cable and thus clamps it tightly.

At the moment we do not have any pictures of this.

How do the diameter decreasers work (these are included when you purchase ViaBlue T6 connectors separately)?


These are two rings with different diameters which are only to hold the cable in the center / on the central axis of the connector. Thus, even very thin cables can be mounted in the relatively large inner diameter of the T6s shells. Depending on the diameter of the cable, you can use none, one, or two.

What is “soft-disk technology"?

The soft-disk technology is an advanced damper technology containing special material mixtures and adapted damping values for the best possible absorption.

How do your Cobra sleeves differ from the standard sleeves you offer?

The COBRA designed sleeves are similar in material and structure to the other sleeve designs sold on our website.

The only difference is that the COBRA sleeve is not available for purchase. Thus, if customers see a cable with the COBRA design, they can be 100% certain, that it was handmade in our VIABLUE Germany facility.

Lavricables​

This is a UK company, with its production being based in Latvia. Lavricables specializes in manufacturing silver cables. It was founded in 2012 as a hobby, and over the years it has grown and become one of the, if not the most well-known silver cable manufacturer in the industry. In total, this company offers four lines of cables: Reference, Ultimate, Master, and Grand. The first three offer headphone, IEM, USB, RCA, XLR, speaker, bi-wiring, power cables, and DIY supplies. Because the Grand line is its flagship line, DIY supplies aren’t sold. Besides having the choice between 4 different lines, customers can customize each cable with a number of options: length, silver, headphone plugs, plug, Y-splitter, silk sleeving, and a burn-in service. Above everything, Lavricables is a company that prioritizes customer satisfaction. From my understanding, that and customer support are the two main fields where the focus is on.

Grand Power Cable



Going by the official name of “Grand 30 core Silver mains EU US power cable”, this is the company’s flagship power cable. It is a braided 30 core silver cable. Out of those 30 cores, 20 are made of AWG 28 5N solid silver wire. Out of those 20, 10 cores are used for the active line and the other 10 are used for the neutral line. The other 10 cores are made of silver-plated copper (0.3 mm diameter) and are used for the earth line. The cable is terminated with rhodium-plated plugs. Though the plugs are high-quality and heavily resemble Furutech plugs, they are in fact not Furutech. For insulation, it uses high-grade Teflon. The manufacturer claims that “the unshielded design brings more air & transparency to the soundstage”, “woven Teflon Litz construction is ideal to deliver RFI and EMI rejection and provides low capacitance”, “5N silver transmits electrical signals faster and with less distortion than ordinary OFC”, “high-grade Teflon insulation gives a predominant air dielectric and is regarded as the best insulator for bare cable”.

One of the most prominent physical features of this cable is its flexibility. You can quite literally wrap the cable around a finger! This plus the somewhat thin nature of the cable makes it ideal for tight spots that you would otherwise have a hard time reaching.

I will also say that there are similar cables to this specific model on the market, but they are all considerably more expensive than the Lavri Grand Power Cable.