Earmen ST-Amp’s Review - Solid and Simply Engaging



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


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


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