In this article, I review the Earmen ST-Amp desktop fully balanced DAC, headphone amplifier and preamp. It currently retails for $599 (as of October 2023 the price has been reduced to $399).
Disclaimer: This sample was provided by Earmen for an honest review. All observations and opinions here are my own based on my experience with the product.
EarMen ST-Amp
What’s in the Box
When I opened the box, I found the EarMen ST-Amp and a user manual. That’s it! For some reason, EarMen do not provide either a power cable or a USB data cable with the unit. This means you’ll either need to have spare ones lying around or you’ll need to purchase them separately. I don’t know why they chose to do this (being environmentally aware perhaps) but it’s highly unusual and will no doubt be an inconvenience for some people.
Design
ST-Amp has a distinctly different design aesthetic than EarMen’s portable units (TR-Amp, Angel etc.) This desktop device takes on a more serious demeanour and blends in more readily with other HiFi devices, thanks to its neutral colours.
The chassis is boxy and has a lot of rigid straight lines without any rounded edges. The bulk of the body is matte black while the front panel is a light grey colour. I think it looks classy and I find the style quite appealing.
For some reason, EarMen only included 3 rubber feet on the bottom of the ST-Amp. This results in the unit being unstable and it often tilts when I touch it to flick a switch or plug something in at the back.
The front panel is dominated by a large black volume wheel. This pleasantly weighted potentiometer provides a smooth and consistent action for precise volume control.
Features and Internals
Internally, ST-Amp features a fairly modest ES9280 DAC chip, supporting up to PCM 32BIT/384 kHz and DSD128. It utilizes two TPA6120 operational amplifiers (op-amps) for the headphone output section.
In terms of inputs, there’s a single digital USB input, a single-ended RCA and a balanced 4.4mm input. Available outputs are RCA and balanced 4.4mm. The EarMen ST-Amp works as a DAC/amp/preamp or with the flick of a switch, it acts as an analogue amp.
There’s plenty of power on tap with up to 1.85W from the balanced output. The single-ended output manages 0.5W which will be sufficient for all but the most demanding headphones.
Sound
EarMen developed the ST-Amp as an amplifier first but with the added functionality of a DAC. So, it’s almost as if the ST-Amp can act as two distinctly different devices. It can be your all-in-one desktop solution or it can be integrated into an existing one.
As a DAC/AMP
I spent most of my time using the ST-Amp as an all-in-one, connected to my PC via USB. I was pleased to discover that it works really well with sensitive IEMs; it can go super low in volume before any channel imbalance kicks in. At the same time, the EarMen ST-Amp doesn’t produce any audible background noise or hiss.
Then on the other end of the spectrum, ST-Amp is muscular enough to power my HD650 headphones with ease and with plenty of headroom to spare. I’ll do a breakdown of that and some other pairings later.
So as an all-in-one device, how does the ST-Amp sound? Initially, I started using it for everyday use and casual listening. After a couple of days, I sat down for some critical listening. EarMen products tend to sound different than the multitude of Topping and SMSL DACs I’m so used to hearing. That’s also what I’m hearing with the ST-Amp.
In terms of tonal character, the ST-AMP sounds clean but nuanced. Bass notes are well-defined but authoritative. There’s loads of texture in the lows yet still a natural roundness and decay. Kick drums sound crisp and punchy with trailing edges that fade away naturally.
The midrange sounds spacious and exact but is brimming with engagement. Whether it’s the crunch of electric guitars in Thenighttimeproject’s Rotting Eden or the acoustic guitars and violin in Thurnin’s Ancient Rites, the ambience and naturalness are distinctly evident.
The treble is crisp, open and neutral in forwardness. It’s not exaggerated or forced, lending itself to a smooth yet exciting expression. How it can be so even yet precise at the same time is somewhat of a dichotomy but it’s one that I thoroughly relish.
One thing I noticed about the EarMen ST-Amp was its gloriously wide soundstage and pinpoint imaging. Sounds can project well outside of my headspace while ST-Amp simultaneously creates a stable centre image. The placement of instruments and vocals is precise and combined with the spacing between elements it creates a virtual 3D space that’s truly captivating.
As an AMP
When used as an amplifier the ST-Amp retains its musical character but is transparent enough that you can distinctly recognize the qualities of different sources. For example, when connected to my Topping E70 Velvet DAC, the resolution was even more impressive. I love the sound of the new AK4499EX and pairing it with an amplifier as capable as the ST-Amp lets me really appreciate its qualities.
Using the same E70 Velvet DAC, the Topping L70 amplifier sounds a touch drier than the ST-Amp. Furthermore, the L70 doesn’t sound as rich or as analogue as the EarMen. Switching back to the ST-Amp, I hear more gritty texture in bass notes and a touch of extra air along with a hint more saturation and naturalness.
Pairings
EarMen ST-Amp with Sennheiser HD650
Simply put, this combination sounds incredible. The bass is defined and textured. Sounds spread far to the left and right in an expansive soundstage. Instrument timbre is spot on and vocals sound expressive and natural. The treble is precise but never fatiguing. I could happily live with this setup as a daily driver.
EarMen ST-Amp with Hifiman Sundara
The first thing I noticed about this pairing was the fullness of the bass. ST-Amp sounds divine with planar headphones. Once again, I was impressed with the amount of texture in the bass, as well as the natural and authoritative weight behind each note. The midrange is detailed and has excellent clarity. Treble notes are crispy and airy with a natural sheen. Upper harmonics float into the ether.
EarMen ST-Amp with Xenns Mangird Tea 2
I hear great sub-bass extension and the ST-Amps signature snappy mid-bass. The midrange is neutral and roomy without any colouration. Electric guitars are crunchy with texture. The treble sounds more forward and energetic with this combo which is something I didn’t experience with other pairings. The soundstage isn’t especially wide but there’s a lot of depth in front of the listening space.
Verdict
The EarMen ST-Amp is not just a versatile device that delivers exceptional sound, it is also a piece that adds personality to any desk setup. Its bold, boxy design with rigid straight lines and neutral colours exudes sophistication and elegance. The ST-Amp’s pleasingly weighted volume wheel provides a smooth and consistent action for precise volume control, making adjusting the sound a tactile and enjoyable experience.
But it’s not just about the looks. The ST-Amp is a true workhorse that can handle anything you throw at it. Whether you’re using it as a DAC/amp/preamp or as an analogue amp, the ST-Amp delivers clean, nuanced, and dynamic sound with a wide soundstage and pinpoint imaging. The ST-Amp is not just a device, it’s a partner that allows you to explore your music in new and exciting ways.
Overall, the EarMen ST-Amp is a device with a distinctive personality that is sure to impress any audiophile. With its unique design, exceptional sound, and versatile functionality, the ST-Amp is a device that you’ll be proud to own I am giving it the PAR recommended award.
Specifications
| Inputs | RCA Single End Input | |
| Balanced 4.4 mm Input | ||
| Outputs | SE 6.35mm | |
| Balanced 4.4mm | ||
| Pre Outputs | RCA (SE output) | |
| Balanced | ||
| DAC | ES9280 | |
| Audio formats | ||
| DSD | 64 / 128 DoP | |
| DXD | 384/352.5 kHz | |
| PCM | Up to 384 kHz | |
| SE in -SE out | SE in – BAL out | |
| Input | 2V | 2V |
| Output | 4V-0.5W@32 Ohm | 7.75V-1.85W@32Ohm |
| THD+N | 0.0025% | 0.003% |
| SNR [A-W] | >117dB | >121dB |
| Dynamic range | >117,9dB | >121dB |
| Freq. response | ±0.003dB | ±0.007dB |
| BAL in – SE out | BAL in – BAL out | |
| Input | 4V | 4V |
| Output | 4V-0.5W@32 Ohm | 7.75V-1.85W@32Ohm |
| THD+N | 0.0025% | 0.002% |
| SNR [A-W] | >118dB | >125dB |
| Dynamic range | >118dB | >126dB |
| Freq. response | ±0.003dB | ±0.006dB |
| Dimensions | 170x30x150 mm / 6,69″x1,18″x5,90″ | |||||||
| Weight | 1100 gr / 2,42lbs | |||||||