Soltanus Acoustics electrostatic headphones & amplifiers — Impressions and Discussion Thread
Apr 29, 2022 at 6:16 AM Thread Starter Post #1 of 19


500+ Head-Fier
Nov 28, 2019

Specifications from website (cannot confirm whether they are still valid/same):


Push-Pull Open Back, Circular, Two Way, Adjustable Electrostatic Headphone


Segmented Rigid Wires


2 microns thin, 104mm in diameter, easy changeable capsule

Frequency Response​

from infra to ultra sound range

Electrostatic Capacitance​

90pF (including cable)


177kΩ (including cable, at 10kHz)

Sound Pressure Sensitivity​

97dBC/200V RMS 1kHz

Maximum Sound Pressure​


Bias Voltage​

580V DC

Left & Right Identification​

“L” and “R” indicated inside the arc assembly.

Ear Pads/Head Band​

Genuine Italian Lamb Leather


Silver-coated OFC


620g without cable

I own the Euridiche (flagship), Euridiche 3D (sub-flagship), Mezzoforte (mid-level) amplifier, and the Fortissimo (flagship) amplifier. I also tried the Minima, but it's nothing like the Euridiche and the Euridiche 3D. As far as I am aware, the Euridiche and Euridiche 3D have the largest electrostatic headphone membrane on the market (104mm in diameter). Please correct me if I am wrong.

Website: (it's outdated)
Apr 29, 2023 at 1:18 PM Post #2 of 19
I know personally the manufacturer and developer of Soltanus audio. I listened the Euridiche and the Mezzoforte amplifiers and Fortissimo amplifiers for a week. I have Susvara and Ferrum amp. The differences are clear between Susvara and Euridiche. The size of the stage, the detailes. It was a surprice for me, I would not think before this. My susvara and the Ferrums are for sale now.
Apr 29, 2023 at 1:22 PM Post #3 of 19
I know personally the manufacturer and developer of Soltanus audio. I listened the Euridiche and the Mezzoforte amplifiers and Fortissimo amplifiers for a week. I have Susvara and Ferrum amp. The differences are clear between Susvara and Euridiche. The size of the stage, the detailes. It was a surprice for me, I would not think before this. My susvara and the Ferrums are for sale now.
Thank you for sharing! It's nice to hear from somebody who owns other flagships. I wish we had more people who shared their opinion and experience, especially considering how few have had a chance to listen to the Euridiche.

Euridiche provides a very unique type of sound performance, it's a whole experience.

P.S. Euridiche sounds on a whole different league when paired with the Fortissimo amplifier.
Apr 29, 2023 at 2:25 PM Post #6 of 19
To be honest with you , personaly for me the Euridiche was better in all respects than my loved Hifiman Susvara.
All of devices where at me and listened them a few of my friends. everyone's opinion was unanimous.
Feb 8, 2024 at 8:11 AM Post #7 of 19

General Information​

Euridiche and Mezzoforte Electrostat System

Note to readers, I am not a reviewer, I am more of an enthusiastic tonality chaser, I don't care about specs or graphs, and my admiration for audio gears is based on evaluation of tonality. That journey started over 17 years ago, were I bought and collected tons of gears as seen in my profile.

Some electrostatic headphone owners attest that electrostatic headphones have some unique tonal characteristics that are a bit different than planar or dynamic headphones. There is some kind of fluidity and ease of extracting details and transparency that is difficult to be achieved by some planar or dynamic headphones. However, a lot of electrostats headphones lack in punch in the low end and the sound profile could be thin. I owned some of those electrostat headphones and heard a lot as well besides the ones I owned. Now that is where the Euridiche comes in to throw that formula or perception out of the window.

When I first saw the Euridiche, it reminded me of Audeze headphones in design. On my head, it feels so comfortable, with those huge comfortable lush pads and the good clamping force which is not loose or too tight and thanks god it’s not as heavy as LCD4

I received the Euridiche with its Mezzoforte amp which is an upgraded version than what is published on Solantus Acoustics website, I got it as I was in touch with the local dealer here, and he informed me that my amp will be an upgraded version of what is on the website, such as having balanced XLR inputs and volume bypass and few other technical differences

Design Innovations (words in italic quoted from Soltanus Acoustics website)

“ Sectioned two-way stator design with several advantages:

– With a built-in switch, the tonality of the headphones can be regulated in 3 steps, depending on your preference, record, and used system, in the high-frequency band. (1KHz and above)

– This configuration gives you a real 3D sound field because the high-frequency content is focused from the front side of the membrane to your ears, and not from the center as it usually is, on the headphones.

Air Flow stator matrix design gives you possible minimal air turbulence during air motion through them. The segments are aerodynamically designed, like the wings of airplanes. This way we can eliminate all of the harshness caused by any other perforated type of stators.

The segments of the stator matrix are focused backward directly on your ears, to create a sound stage like a live orchestra in the concert hall, or the loudspeakers in your listening room.

Easily changeable membrane capsule, for lifetime durability of our product. The only thing in the electrostatic driver that can be damaged over years, is the extremely thin membrane. The owner can change them easily without soldering, just with a few screws. That is the reason why the screws aren’t hidden. “

Sound analysis and comparisons

After unpacking everything and examining the build quality, and noticing everything looks pristine. I put on the headphones and pressed the play button, and I was literally surprised from the first few minutes by what I heard, as I focused on examining the tonal character and let me tell you it put a big smile on my face.

So let’s start with the sound analysis

Bass: The Euridiche has a good bass punch with great quality and impact that fills those huge cups in such a delightful way. Its bass is almost as my Caldera in quantity, but with more detail and speed. Bass does not leak into the mids. The bass is so well defined and bodied, this is the first time I hear good bass punch on an electrostat headphone, and as such you can enjoy electronic music or any other bass related genres to the fullest extent.

Euridiche, in comparison to Susvara, sounds way richer in the low end and with more impact and body

Compared to my previously owned Stax 007 v 2.5 to be honest, there is no need to compare both simply because the Eruidiche is a league ahead of it in impact and punch


I will give the best mids award to Euridiche compared to all my planar, dynamic and electrostat headphones. The mids are simply majestic, neutral, and natural with proper body, richness and resolution and have this grandiose presentation that makes any of my other headphones sound veiled and smaller in presentation

Mids on Susvara have good details but lack the body and richness, the Euridiche is simply richer, with the right dose of body, and they are placed perfectly not too close nor recessed, it’s just like how it should be, matching my tonal preferences. The mids are transparent with great resolution, were you simply can capture all the details in the mids with ease. Never harsh nor peaky, just a perfect presentation of mids. My Caldera has good mids in terms of body but lacks resolution in comparison to Euridiche. My focal utopia 2022 has good mids but everything sounds smaller in comparison to Euridiche mids.

The Euridiche is like a crystal clear window into a beautiful scenery


This is where I am reminded that I am listening to an electrostat headphone were I am able to capture micro details in a different level than any of my planar or dynamic headphones. There is a sense of delicacy and air that non of my other regular headphone have. The resolution of the highs is simply captivating were micro details are presented with ease, and never piercing at all. It’s such a great experience to hear a perfect presentation of highs and details. Those micro details that with some headphones are difficult to be captured and remain hidden in tracks, with Euridiche you hear those micro details and there are a lot of songs were I thought those details were not there using different headphones.

Euridiche, compared to Susvara, simply has a more natural presentation in the highs than the susvara and never crosses the uncomfortable levels that the Susvara does. A lot of times when I used my Susvara I became exhausted by its thin profile and those highs that are peaky in different areas. Yes I tried a lot of amps with Susvara such as my Holo Audio Bliss, Felix Audio Envy, Auris Nirvana and so many others, and still Susvara sounds thin and a bit peaky for my preference

Caldera details lack a bit in comparison to Euridiche, were the level of detail is mirrored and projected with more info and resolution on Euridiche


Humongous, simply it has the widest, tallest deepest stage I heard in any headphones, and that huge stage is filled with body and richness

So in conclusion compared to any headphone in my profile, the Euridiche has a grandiose presentation as I mentioned before and that is literally the first impression you will experience when you hear it, with great bass, amazing mids and refined highs and details. It’s simply an amazing headphone

Mezzoforte Amp: (words in italics taken from Soltanus Acoustics website)

Why Hybrid Topology?

Considering the technical background of the amplifier designing, and audiophile requirements, the voltage gain had been realized with the popular ECC82 double triode in harmonic interaction with hand-wounded, wide-bandwidth output audio transformers.

The tube can be replaced by any substitution of the ECC82, even with the best vintage ones, without any need for tuning the unit.

You don’t need a matched pair of tubes, because the Mezzoforte uses only one piece of tube.

The adequate current is delivered by precise operational amplifiers. The amplifier has a short circuit and over-temperature protection.

In this combination, Mezzoforte is capable to drive simultaneously two electrostatic headphones and one dynamic or planar headphone.

The stable and powerful operation is allowed by a double-filtered power supply in capacitance multiplier topology.Our Audio step-up transformers are wounded by hand to ensure the highest quality in the high-frequency range and use extremely oversized cross-section cores, which enables high impedance and outstanding low-frequency reproduction.

The housing is made from solid 6mm and 3mm aluminium alloy sheets, preventing vibrations or generating any eddy currents by transformers.

The housing can be used vertically, to use it
as a headphone stand, and horizontally too, as usual.”

The amp can be used both as an electrostatic headphone amp and as an amp for regular dynamic or planar headphones. And I can attest that it's a great amp for planars and dynamic headphones as well. It has a hint of a tube flavor with great body and richness. It can drive most planar and dynamic headphones to their fullest potential.

In conclusion: The Euridiche is one of the most immersive and technically capable headphones I heard to this date. The resolution, imaging and tonal character makes it my favorite headphone in my collection and as such it gets the most play time of any headphones I own and it works well with all genres

The headphone comes installed with one pair of pads, however you can ask for a different pad to be installed or you can buy an additional different pair of pads

So its either a pair of leather pads or a pair of hybrid pads ( which is made of Velour + Italian leather ). All my impressions above were based using the hybrid pads. Included are as well sponge inserts that you attach to the pads and those affect the bass if you want to have a different signature

Music used

  • Leonardo Cohen – You want it darker
  • Daft Punk – The game of love
  • Massive Attack- Angel
  • Malia- Celestial Echo
  • Yello – The vanishing of Peter Strong
  • Metallica – If darkness has a son
  • Depeche Mode – The Bottom Line
  • Adele – Hello
  • Arab Strap – The Turning of our Bones
  • Eagles – Hotel of California
  • Guns & Roses – Sweet child of mine
  • Beck – The golden age


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Feb 10, 2024 at 3:53 AM Post #9 of 19
Feb 10, 2024 at 11:59 AM Post #10 of 19
It would be very good to compare to the Warwick Aperio!
the same dealer who brings Soltanus brings warwick, and I compared it to bravura, and the Euridiche - mezzoforte is on another league in dynamics, bass, mids and stage

He does not have the Aperio to audition so I do not know about that
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Feb 10, 2024 at 8:17 PM Post #11 of 19
I'm a little bit curious about these, due to the large driver size.
Might consider picking one up after I try out the Aperio.
Feb 11, 2024 at 2:03 PM Post #12 of 19
Feb 13, 2024 at 9:12 AM Post #13 of 19
Feb 18, 2024 at 6:35 AM Post #14 of 19
This looks like a interesting pair of headphones. Pretty heavy though but interesting. This looks like what I imagine Audeze to make their ES to make. I wish I could try these for a while to compare them to STAX SR-9000
on my head the comfort level is great and I really do not find it heavy at all
Apr 5, 2024 at 5:00 PM Post #15 of 19
I seriously can't stress enough how great and amazing these headphones are, I sold my susvara and caldera as they are not on the same level

This brand needs more recognition
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