EarMen ST-Amp

EarMen ST-AMP​

EarMen ST-AMP
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Prelude:
There are companies that simply do not need to be introduced, one of such companies, despite their still young age in the pages of history, is EarMen, proving at every step that a small sea can be beautiful. By constantly breaking the barrier of technological limitations, it proves how important it is to approach each component in order to create and achieve success. Today we will take a look at their next creation, EarMen ST-AMP. Initially priced at USD 599, it is now available at an excellent and very competitive price.



Unboxing and execution:
The rigid cardboard packaging contains the device itself, which is a medium-sized body, and a short operating manual. It’s a pity that there is no power cord, but on the other hand it allows us to reduce the amount of electronic waste. The device itself is elegant and aesthetic, and the quality of workmanship is at the highest level. On the back there is a USB B input, unfortunately also without the appropriate cable in the set, a 4.4mm balanced input and output, an RCA input and a pre RCA output. On the front panel there is a button to turn on the device, a digital-analog switch, a large jack output and a balanced 4.4 mm output, as well as a solid-looking potentiometer operating in the analog domain. Actually, that’s it for technical issues. It is worth noting that the size of the ST-AMP is perfect for placing, for example, a TRADUTTO DAC on it.


Sound:
DAC Mode:
The DAC implemented in ST-AMP is a well-known solution from ESS, but its selection is not accidental, and the timbre and signature perfectly complement the overall tuning. In this mode, if we use the built-in transducer, we get a complete and entertaining sound, perfect for quiet listening. The amount of information is huge, the detail and dynamics are at the highest level. And the pre output ensures great results.

Bass: The bass itself is fast and dynamic, and its resolving and entertaining character, close to realism and natural-neutral timbre, perfectly reflects the idea of tuning the EarMen. There is a lot of bass, and the base of the lower bands is clearly noticeable. It is an entertaining and engaging musical message that allows us to engage with the music effortlessly. Not for a moment did I feel overwhelmed or overexposed to low frequencies, which I highly praise EarMen for.

Midrange: Extremely clean, close to neutral. Where I could really feel the advantages and craftsmanship of ST-AMP tuning were the vocal sections, where the realism of the sound exceeded my wildest expectations. The amount of detail and information turned out to be more than enough to enjoy beautiful and emotional music. It’s amazing how dynamic and encouraging music can be. The sound stage generated by the st-amp is really large with great width and pleasant depth, which allows me to become an element of my music and its integral part. High neutrality will also allow us to enjoy our music as it really is.

Treble:The highs were smooth and consistent, and the resolution exceeded my expectations for this price point. In the higher tones, in addition to great resolution and neutral transparency, I noticed a lot of air without unnecessary coloration or artificially increasing resolution at the expense of sound. I really like this approach to tuning and it’s something every manufacturer should strive for. Pop and jazz songs sounded extremely engaging, and the separation and resolution of the instruments were exemplary.


AMP Mode:
First of all, let’s start with the fact that ST-AMP only seems to be a simple device, because despite the lack of gain control and a large amount of power in the balanced mode, it is able to detect which socket is currently loaded. We will certainly not run out of power, although the SE output has much less power, which allows us to easily use IEM headphones for which excess power is not always desirable. Let’s move on
EarMen ST-AMP paired with EarMen Tradutto DAC.
As for Tradutto, you can read my full review in the next article. This is one of the best DACs up to PLN 1,000 and one of the best implementations of the SABER converter on the market, in my opinion. ST-AMP itself is quite neutral and perfectly reflects the character of the DAC itself. The sound has become much more resolved, deeper and more musical. Of course, I like the stock ST-AMP configuration, but Tradutto took the sound a few classes higher. The resolution has become noticeably better. I think these devices work great together.
ST-AMP paired with EarMen angel DAC.
In this combination, the sound became even more linear and smooth, the neutrality of Angel translated into an even more analytical and resolving presentation. Tradutto resulted in a more musical and dense sound, while Angel resulted in an even more neutral and technical side of the sound.


Comparisons:

EarMen ST-AMP (599USD/200USD) VS xDuoo TA01B (150USD)
I took the liberty of comparing these two amplifiers because the current price of the ST-AMP is close to my favorite DAC/AMP with a tube, which is the old and no longer produced model from xDuoo TA-01B. xDuoo is a darker, more compressed, but also definitely warmer amplifier, so overall, in terms of technology and resolution, the ST-AMP is definitely the winner, but the TA01B defends itself with a tube color, which I personally like very much, but it is not so universal and versatile. like tuning ST-AMP especially when paired with Tradutto.

EarMen ST-AMP (599USD/200USD) VS HIFIMAN EF600 (799USD)
Overall, the EF600 has much more power, which is its huge advantage, but at the same time it makes it unsuitable for in-ear models, in this respect ST-AMP is much more affordable. When it comes to the DAC section, the R2R in the EF600 is definitely something amazing. However, ST-AMP has better technical sound parameters, so it all comes down to individual preferences. Personally, I cannot imagine music without both devices, which are completely different from each other and at the same time complement each other perfectly. That’s why I can’t pick a leader and I recommend both devices as something really worth attention.



Summary:
EarMen has once again proven its position in the audio scene. ST-AMP at the original price of USD 599 was an extremely interesting proposition, and at the current price it is simply the undisputed number one. It is a great and complete device both as a stand-alone DAC/AMP, as a DAC with a pre function, or finally in my favorite role, i.e. a stand-alone amplifier. The headphone outputs are so well thought out that we can use virtually any type of headphones. The amount of power is more than enough for most headphones. The sound itself is close to neutral, but a realistic and engaging presentation has not been forgotten. This is undoubtedly one of those amplifiers that charms you and makes you addicted to it, just like the EF600. That’s why I highly recommend auditioning. The only thing I would change is to add a few percent to the price and make sure that the buyer does not have to worry about additional accessories. It would be good to see a power cord and at least a basic 4.4-4.4 AUX in the box. However, the sound and functionality completely compensate for this minimal drawback. My final assessment of ST-AMP is as follows: it is one of my favorite amplifiers, so I really recommend it. When it comes to the DAC section, it is well implemented, but it sounded best to me as a trsdutto DAC.

The EarMen ST-Amp was kindly provided free of charge in exchange for an honest review.
I didn't receive monetary or any other kind of compensation and I don't use affiliate links.
The EarMen ST-Amp retails for $599 or €599 and you can order it from the EarMen online shop.



EarMen ST-Amp

EarMen are mostly known for some of the best sounding portable headphone DAC/amps like the Colibri or the Angel but lately they have also been expanding to include desktop devices like the CH-Amp.
The EarMen ST-Amp is the latest addition to the family, a fully balanced desktop headphone amplifier with a preamplifier option and an integrated DAC.

Technical specifications

The amplifier is fully balanced and moreover the exact same topology is used for single ended signals, so they become balanced in a special way with almost no phase shift, additional noise or THD, so the sound from the SE output does not lag behind the sound from the balanced output.
The headphones outputs are powered by two TPA6120 operational amplifiers, which have proven to be excellent in the audiophile world.
To make the experience complete, a high-quality balanced ALPS potentiometer is used for greater sound transparency.
The power output of the 6.35mm jack is 4VRMS - 0.5W/32Ω and that of the 4.4mm jack is 7.75VRMS - 1.85W/32Ω, plenty to drive most headphones.



The digital to analog conversion is handled by a single ES9280 DAC chip by ESS technology and supports PCM up to 384 kHz and DSD128 while MQA decoding is not supported.

At the heart of the device itself is a noiseless linear power supply with great stability, so it can easily provide enough power even for the most demanding headphones.
Apart from the special topology of the amplifier, the power supply is worthy of excellent characteristics even at full power, which is often not the case with most amplifiers, so in their specifications you can find measurements but at half power.



User interface

On the back panel of the device there are both single ended and balanced line level inputs and pre-outputs.
So the ST-Amp can be used as a headphone amplifier and a preamplifier both from the embedded DAC and the line inputs to accommodate different use scenarios.
The user can't bypass the volume control and use it as a fixed line output.
To keep size as compact as possible, EarMen have opted to use 4.4mm jacks instead of 3-pin XLR while the digital inputs are limited to a USB type B plug.
At the front face there are two switches, one for powering on/off and the other for selecting between the digital or the analogue inputs.
The center is dominated by the large aluminum knob of the potentiometer, which has excellent feedback, and next to it there are the two headphone outputs, 4.4mm balanced and 6.35mm single ended.

Build quality and appearance

The EarMen ST-Amp measures just 170x30x150mm so it is compact enough to fit virtually everywhere without occupying too much space, you can place it at your desk combined with a PC or at a bedside table with your phone as a source.
The chassis is made from thick aluminum that also acts as an EMI shield but the appearance is rather ordinary and industrial, the ST-AMP reminds more of studio gear rather than a luxurious home appliance.
Build quality and finish are excellent but the chassis has sharp corners and it is a little unstable because there are only three rubber feet underneath rather than the usual four.
This is a high-end approach that is regularly used in larger devices because it offers better vibration isolation but in the compact sized ST-Amp, where you frequently plug and unplug headphones, it doesn't work very well.



Power output and associated gear

The EarMen ST-Amp was left playing music for about 100 hours in order to settle down.
I have used a variety of headphones like the Focal Clear Mg, HiFiMan XS, Sennheiser HD660S2 and Meze 109 PRO both from the balanced and the single ended outputs.
All the headphone cables are of pure silver made by Lavricables.
External sources for testing the analogue inputs included the iBasso DX320/AMP14, Cayin N7, Aune X8 XVIII and the FiiO R7.

The claim of EarMen that the sound quality of the single ended output is very close to that of the balanced is true indeed but it should be noted that the balanced has the lead with more openness, better holography, sharper imaging, increased technicalities and greater dynamic impact.

The EarMen ST-Amp is powerful enough and will not have a problem driving most of the headphones minus some very inefficient ones.
The noise floor is barely audible, the amplifier is very silent with a black background that makes it suitable for use with sensitive earphones and helps a lot with detail retrieval, allowing for the finest nuances to emerge from the depths of the recording.
Of course there are more powerful headphone amplifiers at this price point but given that the TPA6120 is used, the EarMen ST-Amp power output is at the top limit of what this particular op-amp can provide as it maxes at 8V - 2W/32Ω for a balanced configuration.



Listening impressions - Headphone amplifier

You can use the EarMen ST-Amp either as a standalone headphone amplifier with a source of your choice or as an all-in-one DAC/amp through the USB input.
And while the embedded DAC is an easy to use and very good sounding solution when nothing else is available, it is the headphone amplifier that is the main feature of the ST-Amp and it really shines with a source of higher quality than that of the internal DAC.

The audio performance of the headphone amplifier is truly exceptional, the EarMen ST-Amp is linear and transparent with uncompromised source fidelity while at the same time it manages to present a balanced, natural and organic sound signature with plenty of realism and harmonic intensity.
The sound is full bodied with a weighty and impactful bass that has excellent control, it is fast, tight, and well defined with deep layering and very contrasted dynamics that add great realism to more demanding material like large scale symphonic works.
This recent cycle of the Carl Nielsen symphonies sounded really enjoyable and glorious with the Meze Elite driven by the EarMen ST-Amp and fed by the Cayin N7 line-out.



The mid range is very open sounding and articulated with plenty of harmonic variety and natural timbre, it sounds musical, engaging and emotionally involving with great tonal balance and a touch of warmness.
The treble is transparent and energetic, the amplifier is not short of extension but it doesn't induce any brightness or emphasis.
Detail retrieval is very satisfying while the EarMen ST-Amp doesn't sound analytical or artificial.
The truth is that the EarMen ST-Amp features one of the best implementations of the humble and commonly used TPA6120 op-amp with an audio performance that is more analogue sounding and less artificial than in some THX implementations of the same chip.
It may not sound as detailed, transparent, refined and resolving as its THX counterparts but it presents the music in a more expressive and communicative way, something that works very well with classical and jazz.
Still, the EarMen ST-Amp is very good with every other music genre but there is the chance that someone might prefer a more sparkling and luminous presentation that THX amplifiers can offer.



Listening impressions DAC/amp

In the case that you need to add more energy and brio to the sound, you may use the internal DAC which offers more agility and sharpens, it is a touch brighter and leaner than the standalone amplifier, less warm and smooth so it may better suit certain headphones or types of music.
The basic sonic qualities remain, more or less the same and close enough to the amplifier performance but you lose some of the timbre naturalness and the analogue character of the sound.
There is a difference also in the soundstage presentation, the amplifier can sound very holographic and immersive, given that a potent source is used, when the internal DAC can't compete at the same level.
You don't have to use something expensive, the combination of the Aune X8 XVIII DAC with the ST-Amp sounded better than the internal DAC when I was listening back and forth to this recent recording of Mahler's second symphony.



Compared to the FiiO K7 with the FiiO PL50 ($350 total)

The FiiO K7 is a fully balanced DAC/amp all-in-one desktop device without an internal linear power supply but you can add the FiiO PL50 external LPS to enhance the performance.
The FiiO K7 and PL50 combination is $350 so it is a whole $250 cheaper than the EarMen ST-Amp but you are buying two devices that occupy more real estate than the ST-Amp while they are not so visually appealing.
The K7 features a balanced headphone amplifier that also uses two TPA6120 op-amps in a THX certified implementation with 2W/32Ω of power output and two gain settings.
The digital conversion is handled by dual AKAK4493S chips with an XMOS dedicated receiver that supports PCM 384kHz-32bit and DSD256.
Except for the USB input, the K7 has coaxial and optical digital inputs so it is more versatile but the analogue line inputs and outputs are limited to a single ended RCA and not balanced.
So in this regard, the EarMen ST-Amp is better suited for use with a really balanced source because it keeps signal integrity without performing any conversion.
Sound performance comparison should be splitted in two sections:
As a DAC/amp, the FiiO K7 offers better sound quality with more natural and organic timbre, better technicalities, more refinement and resolution.
But as a headphone amplifier with an external source, the EarMen ST-Amp is definitely the leader by a fair margin.
The sound has more analogue and organic qualities to it, the timbre is considerably more natural, the soundstage is grander and more holographic with sharper imagining and the overall technicalities are a step above that of the FiiO K7.
The EarMen ST-Amp is also better as an analogue preamplifier for driving powered monitors especially if a balanced path is desired.
It would be fair to conclude that the EarMen ST-Amp is an excellent headphone amplifier with a DAC as an extra complementary feature while the FiiO K7 is an excellent DAC/amp with an analogue input/output as a bonus.



In the end

The EarMen ST-Amp is an ode to simplicity, it is a proof that a skilled audio engineer can use the most common audio parts to make great sound without having to go discrete or improvise exotic topologies.
There are so many competitive products that use the same op-amps with the EarMen ST-Amp but few of them can sound equally good, at least in the pure amplification stage.
The EarMen ST-Amp is an excellent sounding headphone amplifier and analogue preamplifier that can also double as a DAC/amp when a better source is not available while it is compact enough to fit virtually everywhere.
Straight and simple, the EarMen ST-Amp is one of the best balanced headphone amplifiers in its respective category.

Test playlist

Copyright - Petros Laskis 2023.

General/Packaging/Build
For those who are not familiar with Earmen, Earmen is a company registered in the US, and a subsidiary of Auris Audio which is a high end Serbian brand that builds amplifiers as well as headphone amps, similar to Auris Audio, although Earmen is registered in the US, all of the products are made in Europe to uphold a certain quality standard.

I have the ST-Amp with me today, a fully balanced amplifier, although it has a DAC (ES9280) in it, its strength lies on the amping section rather than the DAC, while it is certainly good to have for those who are on a budget or looking to get an external DAC to fully utilise the amp of ST-Amp.

Build quality of the ST-Amp is solid, switches are not wobbly, the input and output ports are gold plated and have solid connection (doesn’t come off easily). The only complaint that I have is with the positioning of the anti-slip rubber pad which formed a triangle, which in my opinion isn't that stable as it can easily topple if you accidentally knock it or if you have a thick power cord, it may be an issue as well. The amp itself has a noiseless LPS (Linear Power Supply) built in, which is something that i personally preferred instead of having a separate power brick dangling around

The ST-Amp came in a bare minimal packaging but is well protected, one box contained the ST-Amp, while another layer of box served as a protection layer. It doesn’t come with any power chord nor usb cable unfortunately, but for someone who’s already spending this much amount of money, they should already have several power cord or usb cables laying around, but nonetheless, it’s good to have so a first timer can enjoy the package right out the box.



Technical Specifications grabbed from ST-Amp’s product page
Full product information


IEMs/Headphones/Equipments used for this review

• Final Audio Heaven II 3.5mm
• Kiwi Ears Orchestra Lite 3.5mm
• Kiwi Ears Quartet 3.5mm
• Hidizs MS5 4.4mm
• Earmen Angel -> Earmen ST-Amp
• Xduoo XA-10 -> Earmen ST-Amp
• Sony WM1A -> Earmen ST-Amp

*Earmen ST-Amp is sent over by Miroslav from Earmen for the purpose of this review. I appreciate the opportunity given



Foreword
My review is solely based on what I hear via my equipment and I never consider my reviews to be objective in any way rather a subjective approach. Do take into consideration that everyone’s ear anatomy is not the same, so the psychoacoustics perception might be different as well, but i believe it will not stray too far. I have used the Angel for several months prior to writing this review.

Notable Features

• No loud popping sound upon switching the amp on or off
• Clean and dark background, no audible noise floor even on Hidizs MS5, which has quite low impedance at 5.3ohm, no noise/hiss at all
• Very very little channel imbalance at low volume, pretty much can be ignored even for IEM users, 3rd lining onwards there will be no imbalance anymore, unlike the implementation on some other dac amp, where it is either too soft or too loud, this is not the case here with the ST-Amp

Sound Impression
Listening to both the SE and BAL out, it’s safe to say that the SE doesn’t sound bad compared to the BAL out,, except slightly lacking in terms of dynamics, which is expected from SE output, i have tested some dac/amp which i shall not name to remain neutral, the SE output sounded bad compared to the BAL out, it is as if the SE’s circuit is designed badly and the focus is only on the BAL out. This is not the case for ST-Amp, both are sharing the same topology with almost no additional noise or THD as stated from Earmen, which I can personally attest to.

DAC Amp Combo

• Utilising the internal dac of ST-Amp, which is the ES9280, the DAC exhibited clean lows with good enough texture, sufficient punch and good resolution and dynamics, tonality wise, it is on the slight cool side and it has very good synergy with my transducers that has warm signature, for those with neutral signature, the sound is very dynamic and enjoyable when you feel the need to tap your foot

Amp + Xduoo XA-10

• Operating as Amp only, the ST-Amp is very revealing, uncolored, as well as dynamic. It bring out the characteristics of the DAC connected to it, take Xduoo’s XA-10 for example, which has dual AK4493 DAC, on its own, it doesn’t sound engaging, lows lacks a little texture as well as punch, resolution sounds a little lacking as well, when paired with the ST-Amp, the difference is day and night and i’m not kidding, very clean presentation overall while retaining the AKM’s “flavour”, resolution is also much better, the performance of this amp is simply excellent!
• Bass has better texture and slightly more weight to it, treble has good energy to it while maintaining its smoothness and dynamic

Amp + Earmen Angel

• Earmen Angel itself is an excellent device which i have also reviewed previously, it exhibits very clean and good dynamics
• Paired with ST-Amp, the dynamics of Angel is another step up from its internal amp, it sounds more dynamic, also a little more analytical, and transparent compared to its internal amp
• The reason i said what i said above is because i used the Final Audio’s Heaven II, which is a single BA IEM, listened via ST-Amp’s dac and amp combo, bass is slightly lacking and doesn’t have good texture/definition, switching over to Angel, i can immediately notice the difference in the bass, more texture, sounds fuller and a little bit more punchy, as well as overall resolution and imaging
• Bass has got more punch compared to Angel’s internal amp
• Treble is lively and nuances can be picked up easily, analytical yet enjoyable at the same time

Pairing impression with various Transducers
Final Audio Heaven II

• Heaven II is a single BA IEM and the tonality is slightly on the warm side and bass lacks a little extension due to it being a single BA
• Pairing it with the ST-Amp, somehow the bass sounds fuller and has a bit more extension, the treble also have slightly better extension to it
• Soundstage and imaging is improved a little as well

Hidizs MS5

• MS5 has very low impedance and quite picky in terms of source, i have paired it with iFi’s Gryphon, Go Blu, XA-10, and they all hiss whenever i plug it into the 4.4 port, I’m very surprised when i plug it into 4.4 port of ST-AMP, it doesn’t hiss
• Bass sounds fuller and good punch, treble on MS5 for certain song have slight sibilance, with ST-Amp, it seems to be very well under controlled and kept at minimum (bearable level for my listening preference)
• Precise imaging as well as slightly bigger soundstage

Kiwi Ears Orchestra Lite

• Despite being a full BA set, it doesn’t exhibit any noise or hiss when i plug it i
• Orchestra Lite is another set that’s safe sounding by nature, pairing it with the ST-Amp seems to be a great choice, the dynamics are improved and it is certainly a little more fun sounding now
• Bass is tight and well controlled, sounds fuller as well
• Detail retrieval and staging is excellent

Kiwi Ears Quartet

• A hybrid set with 2DD and 2BA config, default dip switch configuration, bass is fast and tight, full and sub bass has good extension as well
• Treble doesn't sound harsh
• Very good imaging and soundstage
• ST-Amp somehow makes whatever that’s plugged into it sounds good

Final Thoughts
My experience with Earmen’s product has been good, ST-Amp is no exception. As a Dac/Amp combo, although the in-built DAC is not a high performance DAC, it provides good enough sonic performance for users who are conscious about desk space.
However, the strength of ST-Amp lies in the amp itself, it is very clean and packs enough punch for most IEMs and efficient headphones out there.

The overall build quality is solid and it certainly looks like it is built to last. With all that being said, there are some drawbacks such as the lack of gain switch, as well as bundled accessories (nitpicking)

Still, without any doubt, I absolutely recommend the ST-Amp for those who are looking for a clean and dynamic sounding dac/amp.

Head to the link below if you are interested in getting a unit yourself
Earmen ST-Amp- Non affiliated
Earmen ST-Amp Product Page

Introduction

Almost everyone is familiar with EarMen, a brand that was born out of an audio company (Auris Audio) dedicated for over a decade to developing tube amplifiers, working to perfect a neutral, natural and clean sound. Away from the madness of achieving the most perfect measurements that other brands strive to reach, EarMen is driven by delving into sound above all else. As a result of this working philosophy, the new EarMen ST-Amp DAC/Amp has been born. It is a fully balanced desktop headphone amplifier with the option of a preamplifier and integrated DAC. The same topology is used for the SE signals, so its quality does not lag behind the sound of the balanced output. TPA6120 operational amplifiers and an ALPS potentiometer are used. As DAC it uses the Sabre ES9280 chip, capable of decoding files up to 384kHz. Let's see what other surprises this new product brings.



Specifications

• Inputs: RCA Single Ended, Balanced 4.4mm.
• Headphone outputs: SE 6.35mm, Balanced 4.4mm.
• Pre-outs: RCA Single Ended, Balanced 4.4mm.
• DAC: ES9280
• Audio Formats: DSD 64 / 128 DoP. DXD 384/352.5 kHz. PCM up to 384 kHz.
• Dimensions: 170x30x150mm (6.69 "x1.18 "x5.90").
• Weight: 1100 gr. (2.42 lbs).

Packaging

The EarMen ST-Amp came protected in a white cardboard box, as external custom packaging. The actual product box is black, textured, with dimensions 208x208x95mm. As usual it was protected by transparent cellophane. On the front side there is only the logo and brand name inscribed in silver ink. On the back side there is a large black label attached, containing the specifications, a description of the features, the logos of the formats it can play and some barcodes and QR codes. Removing the cellophane reveals the pleasant texture of the box. Inside is the user manual and the ST-Amp, protected by a grey foam sheet, on its top and a perfect mould for the rest of the sides. There is nothing else, except for a silica gel sachet. The presentation is totally minimalist and cable-free. It’s surprising that a product like this and at this price level does not come with any cables, not even power cables.



Construction and Design

The ST-Amp stands out because of its front design. Actually, the rest is a classic rectangular aluminium case. But it is the faceplate that adds to the charm of this product. It is a greyish-white colour, with a matte, subtly rough texture that looks like unpolished ceramic. In each corner there are 4 black Allen screws that add contrast. On the left side, there is the product branding, in black ink. On the same side, but at the bottom, is the metal toggle type on/off switch. Below it, there is a white LED indicator light. To its right, halfway down the large black ALPS potentiometer, there is another switch just like it. This time there is no LED and its use is to switch between pure amplifier mode (position A) or DAC/Amp (position D). The potentiometer is in the centre, is large and offers a good level of resistance to movement. It is positioned slightly at the bottom of the front panel and is also a good size in depth, making it easy to grip and position. It is subtly tapered and its base is an almost flat cylinder of larger diameter, on top of which is the small white bar indicating the position of the volume. Around it, on the faceplate, there are multiple bars to mark the volume level. As it happens, the potentiometer rotates beyond where these bars start or end. In other words, its travel is greater. To the right of the potentiometer, there is an oval with a sloping upper side, increasing to the right. This oval is recessed by a few millimetres and inside it is, first, the 4.4mm balanced headphone output, gold-plated; second, the 6.35mm SE headphone output, also gold-plated. Above the SE output, at the top, is the model name, inscribed in black ink.
On the rear face are the connections. Starting from the left, at the bottom is the balanced 4.4mm input. Next to it, the two RCA inputs, vertically. Symmetrically, the pre-outs are arranged, first the RCA and then the balanced 4.4mm output. All these connections are gold-plated. Next to it is the USB type B input for connecting a source, such as a PC. Then there is the input voltage selector (115V/230V). Finally, there is the power connector. The back plate is black and polished, fastened by means of 4 round-headed Allen screws. The body of the amplifier is also black, but with a slightly rough texture, which gives it a slightly matt look and prevents finger smudges.
Like the presentation, the design is minimalist, but the design of the front panel stands out in a big way. The very, very light grey colour of it, its matt ceramic touch, which gives it a very special roughness and feel, the toggle switches and the headphone outputs in that slightly sunken oval, give it an elegant, very special touch. All this, together with the large central potentiometer, stands out in a powerful way.
The design is very elegant and attractive, but it retains a very striking sobriety, which does not lose an ounce of robustness.
Finally, it is interesting that it has only three legs, two at the front and one at the back, in the centre. Each leg is a rigid cylinder with a semi-spherical rubber base of a smaller diameter.



Connectivity

The ST-Amp can be used as a pure amplifier or as a DAC/Amp. For use as DAC/Amp a USB cable can be connected to the following compatible operating systems: Win10, Win11, Android, MAC, iOS. It does not have ASIO drivers.
Can be used as a pre-amplifier, using the 4.4mm RCA or BAL outputs.
Can be used as a headphone amplifier, using the 4.4mm RCA or BAL inputs.
To power the device, it is necessary to select the corresponding input voltage (115V/230V) on the rear selector switch.



Operativity

The operation is very simple.
There is a toggle switch to turn the device on/off. There is a white LED below it, to indicate that it is on.
There is a toggle switch to select DAC/Amp or Amplifier mode. Set the toggle switch to D mode to activate the USB digital data input. Set the toggle switch to A mode to select the analogue input.
As a pre-amplifier, the front potentiometer drives the volume of this output.
In amplifier mode, the balanced input takes precedence. If it is switched on, the SE input is disabled. To listen to music from the SE input, the balanced connection must be removed.
The headphone output can only have one active connection. To listen to music from the balanced output, nothing must be connected to the SE headphone output.



Measures

The measurements were made using the device's internal DAC.
One thing that surprised me about the EarMen ST-Amp is that it has no gain selector. Compared to a cheaper device like the ifi Zen Can, which has 4 gain modes. In this respect, the ifi is much better suited to drive more headphones, due to this fact. How does the ST-Amp cope? Well, according to my measurements, in SE, with the pot at 3h, the output voltage is 600mV. While on BAL, with the pot at 3h, the voltage is 1.12V. This implies that there is a lot of potentiometer travel for use with sensitive headphones. But that, on the other hand, the voltage increase is very large from this point on: in less than a quarter turn, the voltage rises by 3.5V for SE and 6V for BAL. A very big jump. The potentiometer is very smooth up to this point, then the increase is very large. That makes the last quarter turn suitable for use with high impedance headphones, but with little room to move.

No Load SE

With the potentiometer at maximum without load the voltage value is above 4V (4.29 at 1kHz).



15 Ω SE

Actually, the ST-Amp is quite good for low impedances per SE. It is capable of delivering 3.17V, which implies a power of 670mW and 210mA. A very high value.



33 Ω SE

The ST-Amp meets expectations and gives the maximum at this impedance: 4.22V is 540mW, more than specified.
With these values, the output impedance for SE is below 1Ω.



100 Ω SE

I have not made measurements at this impedance because as at 33Ω the voltage peak is already reached, at 100Ω the same thing will happen. So the power for this value of resistance would be 180mW.

No Load BAL

With the potentiometer at maximum without load the voltage value is above 8V (8.58 at 1kHz).



33 Ω BAL

It was a bit complicated to make measurements with low impedances, as the potentiometer at the high end of the range, with very little rotation modifies a lot of voltage, it was easy to reach the cut-off due to thermal protection. According to specifications it should reach a voltage of 7.75V, very close to the maximum. The truth is that I have reached 7.34V, which means a power of 1.63W, which is a very high value.



100 Ω BAL

For 100Ω per BAL the voltage is above 8V (8.4V at 1kHz).
The output impedance for BAL, averaged over all measurements, is less than 1Ω.



Respuesta de Frecuencia

I have made measurements with the potentiometer at 9h, 12h, 3h, 4h and maximum by SE. It can be seen that at some volume levels there is a slight difference between channels. While at maximum there is no difference.
On the other hand, it can be seen that the device has a completely flat frequency response from 5Hz to 40kHz.



Sound

To evaluate the sound of the EarMen ST-Amp I have used my PC with Windows 10 + Foobar 2000 as audio player. I have used the ST-Amp as DAC/Amp and as Amp, connected to the EarMen Angel (via 4.4mm balanced cable) and Aune X8 XVIII Magic DAC (via RCA cables). For comparison, I have also used the ifi Zen Can.

The EarMen ST-Amp can be used as a DAC/Amp (D-mode) or just as an amplifier (A-mode). My impression is that the general purpose of this device is its use as an amplifier. The DAC section is determined by a relatively basic chip in this respect. This is the ES9280, a DAC that is mounted in EarMen's cheapest product, the Eagle. Supported audio formats are 384kHz via PCM and DSD128 DoP. Despite my preference, it has no ASIO driver. But its big advantage is that it doesn't need a driver to be used on Windows 10 or higher.
As an amplifier stage, the ST-Amp is very neutral, which can be seen in its frequency response. In this way, it is very capable of allowing differences between the DACs connected to it to be observed. In that respect, it is easy to differentiate between the internal ES9280 DAC and the Aune X8 XVIII Magic DAC. The ES9280 offers a clean, flat and linear sound, with a simpler, cleaner and smoother descriptive capability. Already, from the low end, the bass texture is smooth, clear, with a punchy but rounded punch, technically quite acceptable. Texture and dynamics are aspects that I notice distinctive, for example, when used with the Aune X8. The OpAmps can be changed on this DAC and the ST-Amp is the perfect ally to demonstrate and bring out the small differences that the change of chips can generate. Compared to the internal ES9280 DAC, the Aune X8 XVIII has a much more pronounced texture in the low end, generating a more descriptive bass, with more body, texture and roughness, something that makes it much more appealing. You also feel that the lower range possesses a superior grandeur, as well as a more dynamic, richer and lusher midrange. In contrast, the internal ES9280 DAC seems more linear in all ranges, even somewhat airier, brighter and cooler. The Aune X8 is more forceful, physical and dense, with a warmer character and a more pronounced texture. That texture gives it an ornamental appeal that may be superior to the internal DAC, because it attempts to offer a richness of nuance that contrasts with the less distinctive neutrality of the ES9280.
By using the EarMen Angel as a DAC, connected via the balanced output to the ST-Amp, the cleanliness of the internal DAC is restored, but superior analytical virtues are added. The sound again gains in dynamics and texture, but with a somewhat cooler, more transparent and more precise profile than with the Aune X8 XVIII. As for the bass produced by the Angel, it has more punch and richness than the internal DAC. Its size is larger and both the accuracy and the level of resolution are better and higher. The level of transparency also feels enhanced, as does the sense of dynamics offered. Relative to the Aune X8 XVIII, the Angel feels cleaner and more linear, with a punchy weight and presence, but with a more natural and pure timbre. The Aune, on the other hand, stands out for its reinforced character, texture and bass presence, something that detracts from its cleanliness and neatness, but adds extra density, body and exuberance. Clearly, its sound is warmer, while the EarMen pair tries to maximise purity, neutrality, but without losing musicality, gaining in extension in the upper area, sounding cleaner and clearer in this part, with a sense of openness and transparency also more discernible.
As you can see, the ST-Amp stands out for being very neutral and makes it easy for the character of the connected DAC to be extended to the headphones. Just as the ifi Zen CAN, from any connected DAC, already imprints a warm, darker colour, typical of the brand, with the ST-Amp none of this happens. On the contrary, it seems to try to maximise the personality of each DAC and not the other way around. In my opinion, this is a feature to be taken into account. If you don't want to add more colour in the sound chain, the ST-Amp is the perfect ally. And in that respect, the pairing with the EarMen Angel is a winning combination. In terms of dynamics, clarity and stage, taking advantage of the balanced connection and the Angel's more neutral and wider purity, you get a larger sound, which expands in brightness and ornamental richness. While the Aune X8 XVIII seems more expressive in the low end, the Angel surpasses it in midrange, tonal richness, mid-note weight and treble informativeness. In this respect, the Aune's density works against it. Whereas the Angel's purity and grandeur is rewarded in the expressiveness of the upper mids and treble.
If I concentrate on one main aspect, the vocals, they sound more muted on the Aune, whereas with the Angel there is a superior liveliness and a higher harmonic extension, which extends the presence of the vocals. The range of the voices is more extensive with the Angel. Starting with the male voices, the accent on the lower part is more subtle, but also fuller. While its expansion towards the higher tones makes its overall representation wider and fuller than with the Aune. On the other hand, the level of dynamics is more obvious, the separation between elements as well. The instrumental distance and the silence between them is perceived as reinforced compared to the Aune. If the sensation of volume is focused on the lower part in the X8, the sonic amplitude stands out, from the mids onwards, with the Angel, generating a sound that is more fluid, clean, clear, luminous, rich in detail and resolution, but it is also more gaseous, volatile and wide. As I say, connecting the Angel is like turbo-charging the ST-Amp's internal DAC, and my sonic preference is much closer to this set than connecting to the Aune, which is a more visceral point, with a more physical and corporeal punch, especially in the low end. The texture and density stand out, as opposed to the size, scene, expansiveness, transparency, level of definition and resolution of the Angel. And, in this duel, the winner is always the EarMen ST-Amp, something that indicates to me that it can still scale further in its final quality, as a superior DAC could even take the connected headphones to a higher level. And therein lies the greatness of this device. While the internal DAC is quite appropriate and sufficient for those who want to keep a clean and uncluttered desktop, the marriage with a pure, technically superior DAC will increase the final sound quality, without the ST-Amp being any limitation whatsoever.



Conclusion

The EarMen ST-Amp is a complete device. An extremely elegant and minimalistic DAC/Amp, which can also be used as a preamp. With a black aluminium body and a very light grey front with a matte ceramic texture, the ST-Amp stands out with a simple, but extremely attractive, striking and distinct design. It features toggle switches and a large ALPS potentiometer, attributes that allow for a high and pleasurable user experience.
As an audio device, EarMen continues to pursue musicality with technical, pure and neutral devices, with the intention of magnifying the sound as much as possible. The concept of the ST-Amp is functional and minimalistic, without too many options and connections. It cleverly features balanced 4.4mm inputs and outputs, supported by an architecture that is also fully balanced. In order to maximise the sound quality that such a construction offers, EarMen uses the same topology for the SE signals, so that they become balanced, but in a special way.
As a single stationary device, the ST-Amp is completely versatile and self-sufficient. Although the ES9280 DAC used may be basic, its implementation, neutrality and musicality are enhanced by the ST-Amp's amplifier stage. However, I can't help but notice that this product is a winner when used as an amplifier. In my opinion, what makes this amp so special is its purity and its ability to not add any kind of colour to the connected DACs. The ST-Amp seems to enhance the sound of the associated DAC, amplifying its characteristics and personality. It really is an amplifier in every respect, not only adding power to the sound of the source, but amplifying its essence and particularities. And, speaking of power, this Earmen has a very powerful SE output, with more than 0.5W demonstrated for 32Ω. The balanced output is no slouch either, and calmly reaches 7V RMS for 32Ω.



Earphones and Sources Used During Analysis

• PC Windows 10 + Foobar 2000.
• Aune X8 XVIII Magic DAC.
• EarMen Angel.
• Tempotec Serenade X.
• Hidizs MS5.
• KiiBOOM Evoke.
• KiiBOOM Allure.
• TKZK Ouranos.
• Kinera Celest Pandamon.
• TinHiFi C2.
• Letshuoer S12 PRO.
• NiceHCK F1.
• BQEYZ Winter.
• Rose QT9 MK2s.
• ISN H40.
• Yanyin Aladdin.
• Penon Globe.
• Rose Martini.

Ratings

• Construction and Design: 92
• Packaging and Accessories: 60
• Connectivity: 75
• Operability: 70
• Sound: 94
• Quality/Price: 88

Purchase Link

You can read the full review in Spanish here

EarMen ST-Amp is a DAC/Amp made by an American Company in Serbia. It costs $599 and provides a lot of power through its balanced output. It is mainly an amplifier, yet don't forget about the built-in DAC.​

​

Introduction to the EarMen ST-Amp review​

Reviewed EarMen ST-Amp is a fully balanced DAC/Amp made in Serbia by an American company. EarMen is a young and dynamic audio equipment company that specializes in producing high-quality and portable audio devices. Founded in 2017, the company has quickly gained a reputation for its commitment to delivering superior audio performance and user experience. Even here, at Ear Fidelity, where we had written a few reviews about their devices.
With a commitment to innovation and quality, EarMen should receive more attention from the whole industry. Their products are sure to impress even the most discerning audiophiles.

Packaging​

Inside the black box of reviewed EarMen ST-Amp, we won’t find much. To be honest, we won’t find anything but the DAC/Amp and manual. There’s no power cord, there’s no USB cable, and there are no RCA cables. It’s a shame because, with the price set at $599, we could expect something to be there. Anyway, the sound quality might make it worth paying this price, even if we had to pay extra for a set of aftermarket cables. Don’t forget that many of us have those cables somewhere at home, so other ones wouldn’t be needed.

Design and build quality of EarMen ST-Amp​

EarMen ST-Amp which we review is an exceptionally made DAC/Amp. It is not looking the same as other products made by EarMen, like Tradutto. It’s not looking the same as their mobile, battery-powered products either. ST-Amp is a brand-new product, from a new series. It looks and feels amazing, with just one, little problem. Reviewed EarMen ST-Amp sits on three feet, so it isn’t that stable. It’s also a little too light, even if it’s really well-built. 2.42 pounds (1.1 kg) is problematic with its stiff switches on the front. Each time I’m turning EarMen ST-Amp on, it gets off the desk at some point. To be honest, I just stopped turning it off, so it doesn’t happen.
Besides that one small issue, the reviewed EarMen ST-Amp is really great. It looks a bit rough, but I like this style — matches perfectly my headphone stand and Audeze LCD-X that I am using as my daily cans. On the silver front, we’ll find two switches, a black volume knob with markers around, and two headphone outputs in a small indentation. It looks great, especially with black screws in the corners. The rest of the EarMen ST-Amp is in satin black, which also looks great, but a little boring.

Tech and I/O​

Let’s talk a little about boring tech. I know there are some fans of this paragraph, but I am definitely not one of them. So, reviewed EarMen ST-Amp is mainly an amplifier, yet it provides a built-in DAC. It is not one of the top models, because it is Sabre ES9280, the same one we could find in $129 EarMen Eagle. It does not really bother me, because the main thing that decides about the sound is the implementation, not the chip itself.
In terms of amplification, EarMen ST-Amp which we are reviewing today provides up to 1.85 Watts through the balanced output. Using single-ended output provides up to 0.5 watts. It is enough for most headphones, especially using balanced output. The amplifier is based on two TPA6120, which are quite popular through audio devices and amplifiers. The volume knob is a high-quality, balanced potentiometer from ALPS. It provides great quality and remains the sound unchanged. At least, this is what EarMen says.
In terms of inputs and outputs, I expected a little more. EarMen ST-Amp which we’re reviewing is equipped with only one digital input, and it is the USB type B. Not gonna lie, I’d really use this as a DAC with a preamplifier for my stereo set, as the sound matched perfectly. Yet, the USB is the only option. Besides, there are two analog inputs and two preamplifier outputs. EarMen ST-Amp provides single-ended RCA and 4.4 millimeters jacks.

How does the EarMen ST-Amp sound?​

EarMen says it is mainly an amplifier, yet I was using it mainly as a DAC/Amp at my PC. Not gonna lie, I am a little tired of using a bunch of devices, and I am trying to reduce it, especially on my desk. So, I will start talking about EarMen ST-Amp as an integrated device, and at the end, I will focus on it as an amplifier.
In a few words, ST-Amp is really lovely and quite universal. It does imply a little of its own sound signature, but it is doing this really politely. It is not like some DAC/Amps that try to be as neutral as it is possible, which can cause sibilants in some situations. Reviewed EarMen ST-Amp is neutral, yet it is not cold and unpleasant to listen to. It provides a lot of details together in a natural manner, the addition of musicianship and something that many people would call emotions.
So, beginning with the bass, which is fairly strong, and nicely extended. It is hard to explain how does the subbass sound, because it connects two things that do not often come together. Smoothness and texture. It provides really nice amount of details, with a small amount of being silk smooth. It may not make sense when I am talking about that, but ii am pretty sure you would get the point once you would listen to the reviewed Earmen ST-Amp. Subbass goes way down with a lot of energy. That’s just wonderful whenever I’m watching some movies, playing games, or just listening to music that contains such low frequencies.
Midbass on the other hand is a little different. The smoothness is decreased, it focuses on the punch and speed. To be fair, that is one of the fastest possible options I have ever heard at this price point without sounding dry. Because you will find a lot of amplifiers that can be fast, but there is no chance they will be that pleasant at the same time. You can hear that, especially when listening to songs like “bad guy” by “Billie Eilish”. This song is really bass-heavy, and some lower-end setups will not provide anything but bass. And it is not the point. No matter what headphones I have tried together with ST-Amp, the result was the same. There was a lot of bass, but the control is awesome.
Kickbass is similar to the midbass, it is fast with a dose of softening which provides that natural feeling. It does not matter whether it is a dry snare drum, some electronic punch or anything else. EarMen ST-Amp just provides a great rhythm that will make you shake your head. Again, without dryness or being cold and too technical. All this combined about bass, I would not fear to combine anything with ST-Amp, as all the options are great. Especially if you would use balanced output, which provides more power, together with an upgrade of everything that I have written above.

The midrange is a little calmer than the low frequencies. It is still natural, but in some cases pushed back a bit. Mainly female voices, like Dua Lipa. They are a little sweetened and muffled. What is interesting, it does not occur with lower or higher voices, like “Tone And I” or Billie Eilish. It is just this specific frequency that does not shine as it could. It might be problematic for some of you, but I would not overthink that part.
Male vocalists are standing at the front all the time. It does not matter if their voice is more like Kendrick Lamar or Masked Wolf. Two different tonalities, same result. They are sounding bold, and full of confidence, yet smooth and pleasant. That is just wonderful about the EarMen ST-Amp. It is the one DAC/Amp that made me listen to the music on the over-ear headphones again.
The details are softly marked. You can hear that they are there but in not so obvious style. It is not because of the lack of technical possibilities, just a natural style. It works really great whenever I am listening to some metal or hard rock, where the amount of sharpness and poor recording might be shocking for some. Reviewed EarMen ST-Amp appreciates music in higher quality, which is well recorded. Details are still a bit soft, yet they sound just remarkable. I can hear all of them without being tired because of its amount. It can happen once in a while when it comes to my taste and preferences.
The treble is once again smoothed and natural. What’s fascinating, with some in-ear monitors, like Campfire Audio Honeydew, which are rather calm and with less high frequencies, the EarMen ST-Amp can provide a small boost in that area. Whenever I am listening to something that provides more high-pitched sounds, they are smoothed and delicate. There is almost no chance of sibilant. It might happen with some headphones like Audio Technica ATH-M50x, which tends to do so. In any other case, I would not be afraid of that problem.
Treble also contains a lot of air and space in it. It is delicate, yet well-balanced. It sounds wonderful, especially with the piano and violins. Drum cymbals are clean and even with the smoothness that comes with ST-Amp, they are able to be harsh in a positive way. With some DAC/Amps or headphones, I can hear that unpleasant abrasiveness, which causes me to change the setup or the song. On the other hand, sometimes I can feel that total smoothness, which is an exaggeration in the other direction. EarMen ST-Amp provides a nice balance, and I’m loving this in this small, Serbian-made device.

Soundstage is one of the most important things in the sound for me. I like when there’s a lot of air, a lot of apparent sources, when it is really deep, but can also play right into my ear. In this case, I have almost all of them, but in a way that isn’t really for me. It is still lovely. The main difference is caused because the width of apparent sources is rather big. There is not much space between them in terms of breadth. It is better with depth.
The layering that is provided with reviewed EarMen ST-Amp is fantastic. When I plugged in Audeze LCD-X using the balanced output, I was just blown out of my mind. This combo provides a lot of apparent sound sources that are set just behind them without mixing them into one sound. In online games, it might be even too accurate because a lot of sounds confuse me more than just one from each direction. When there is too much happening at the same time, I am screwed.
The soundstage is also very precise and broad. It does not have problems with sound sources behind the listener and inside the head. They can go all over. I won’t tell you the title because I do not remember, but when I was watching one movie, there was one shot where the camera was set under the train, right between the rails. That feeling when the railroad train went all over my head was something almost unnatural.

EarMen ST-Amp as an amplifier​

That paragraph will be much shorter than the one above. It is because the sound signature of ST-Amp as a DAC/Amp and as a pure amplifier is really similar. It is still singable, smooth, and natural. Furthermore, it is quite dependent on the used DAC. We can hear a big amendment when we are using different digital to analog converters. If it is colder like Topping D50s and more natural like EarMen TR-Amp or truly analog sounding like my old CD Player, Acoustic Research CD-07 we get three different results. From my experience, it does not happen when we are using THX-based amplifiers, they are not that dependent on the source.

Pairings​

EarMen ST-Amp with Audeze LCD-X​

Audeze LCD-X is my daily driver, so I was using them with the reviewed EarMen ST-Amp the most. It is a combo where everything fulfills everything. I can not imagine a better setup for me, even if I had to choose some really high-end gear. Okay, maybe some R2R DAC with a neutral tube amplifier would do better. It is the setup that makes me enjoy the music and listen to it for long hours without being tired. Even when I am working, there is some podcast playing in the background, some random TV series, and it is all wonderful. That combo is just pleasing, not tiring, and it allows me to cut off from anything else. It is also on the edge of being focused on the music and letting it by my ears. Everything is in place.
The bass is powerful and goes way down to rumble whenever it is needed. Midbass is smooth, yet textured. It does not cover anything in the midrange, as it can happen when LCD-X is way underpowered. Kickbass using single-ended output might be a little too slow, as it lacks the punch. It gets way better using a 4.4 mm connector. The midrange is also smooth, pleasing, and colorful. With some singers, like mentioned before Dua Lipa, it might get a bit dull. Again, that disappears when we are using the balanced output. Details are on spot. They might be a little soft, which is good when we want them to be. If you prefer them to be sharper, you should look at different headphones on THX amplifiers.
Treble is once again delightful. Smooth, accurate, and natural with a drop of analog style. Details are delicate and charming at the same time, but they are not hidden in any way. The soundstage is broad, placed rather near the head with broad sound sources. This setup works out best with hiphop, fresh pop, and jazz. I do not like it in classical music, but that’s my thing. In my dads’ opinion, it is the best in symphonic.

EarMen ST-Amp with Hifiman HE-5XX​

This setup is quite different, especially because the 5XX tends to sound in a more technical, neutral style than the LCD-X. I really like it for gaming or fast music where much more happens in the background. The bass is really fast, it does not lack anything. There is much texture, and great extension in the lowest parts, and the kick is pretty powerful, but sometimes it feels tentative. The midrange is greatly textured, without hissing, and with a lot of details. Vocals are placed a little further compared to the LCD-X, but there is no problem with being dull. The treble and soundstage are fantastic, as the treble is still sparkling without being smoothed or sharpened, as it should sound in HE-5XX. The soundstage once again is different compared to the LCD-X as it provides narrow sound sources. They are similar in the other thing — its precision. Great combo, but I think that reviewed EarMen ST-Amp can do more than the HE-5XX would provide.

EarMen ST-Amp with Dunu EST 112​

Dunu provides us with a really great cable with interchangeable plugs. It allows me to analyze the sound on both outputs. And even if the difference is not that big, it is for sure distinguishable. Some would call them sounding near the Harman signature, and even if I do not like many products with that sound, the EST 112 are still one of the most used IEMs for me. Together with the EarMen ST-Amp, they make a decent couple, as this time I really this how this DAC/Amp thickens the sound. Sometimes in the EST 112 there was too much space and air between the sound sources. ST-Amp fulfills that space by making the instruments wider. It does not take anything from the spacious feeling, but it does not feel like we are levitating in the void anymore. That is for sure a nice addition for me.
The bass in this setup is powerful, yet not leading. Subbass is playing in the background, behind the scene. Midbass together with higher bass is leading the show in this department. And they are doing this really well. The bass is thick, and juicy and provides a lot of fun and emotions to the music. The lower midrange is delicately recessed. It might get hidden behind the upper midrange, especially in some songs with two singers. It does still contain a lot of details, and this time they are greatly marked, but again, without being sharp and unpleasant. The treble depends on the type of connection. Using single-ended output ends with delicate, analog treble. With 4.4 mm connector, it gains a lot of air and shines without sibilants.

Comparisons​

Vs. other EarMen devices​

Well, this one is going to be delicately general, but I do not really think that there is a point in comparing those devices one to one. For me, reviewed EarMen ST-Amp is a comeback to the older models, like TR-Amp, that I reviewed years ago. It has a similar, yet not the same style. It is natural sounding, but this time we get a more neutral version that is closer to new devices, like Tradutto and CH-Amp. Also, the method of presenting apparent sources is closer to the older ones than to the new ones. It is still broad and deep, but each source is wider and more direct. I think the ST-Amp is a wonderful choice for everyone who wants more feelings in the sound compared to the other EarMen product from their current offer.

Vs. SMSL DO300 + HO200​

We all know how SMSL products sound. They are precise, direct, and dead silent in the background. I know that there are people who enjoy that style, yet ST-Amp is not that good in technicalities. It does improve with a better DAC, but DO300 improves with better amplifiers. We could go count like this every time. I would not personally suggest SMSL combo to anything that tends to sibilant, to be cruel, and harsh. Unless that’s what they want. EarMen ST-Amp does sound different, it forgives way more mistakes. There’s no way to say which option is better without knowing someone’s taste. If you prefer a technical, fast, and neutral style, you should listen to the SMSL. If you like the emotions and want to connect with the music, I would give ST-Amp a shot. It is worth it. Trust me.

EarMen ST-Amp review — summary​

Reviewed EarMen ST-Amp is a wonderful option for a very broad spectrum of headphones. It has a really nice amount of power using the balanced output, a great DAC even if it is mainly an amplifier, and is built really solid. It has a delightful, natural yet neutral sound signature that hits me right on the spot. I am trying to be as objective as possible but trust me, it is hard when something feels like it is made just for my taste. EarMen ST-Amp provides a lot of emotions and joy during the listening sessions. At the same time, it is a remarkable companion for work. We can just enjoy the music and be focused on anything we should do at the time.


Absolutely recommended.


Big thanks to EarMen for providing the ST-Amp for this review. I wasn’t paid or asked to say anything good or bad about this product, all of the above is just my personal, unbiased opinion.