EarMen was founded as an arm and sister company of the respected European manufacturer Auris Audio by its founder Milomir “Miki” Trosic with a specific goal: to improve portable listening. Unlike Auris Audio’s catalog, which doesn’t shy away from the super high-end (as the 24-karat gold Hawk tonearm and high-end, hand-crafted array of amplifiers demonstrate), EarMen’s lineup had to be filled with small , affordable batteries. powered and USB DAC/headphone amps designed to give phones, computers and other portable/desktop devices the sonic boost they so desperately need.
But in late 2021, when EarMen had a nice array of such units under its belt, Trosic couldn’t help it; he took the EarMen brand a step further by developing a stack of more serious headphone components for the desktop: the Tradutto DAC, Staccato streamer, and the two-box CH-Amp analog headphone amp we’re taking a closer look at here.
Functions
This is a fully balanced headphone amplifier with a built-in preamp that comes with a separate (supplied) linear power supply unit, the PSU-3. The ‘fully balanced’ design means that incoming balanced signals are not only output intact (albeit amplified), but signals coming in via the single-ended RCA inputs are converted to balanced signals, supposedly with the positive and negative signals perfectly matched in phase. The external power supply, meanwhile, has been developed to provide clean power with “minimum noise” to its headphone amp partner, and also to the Tradutto and Staccato models when needed.
EarMen has used its experience in designing headphone amps, and no doubt Auris Audio’s, to design the CH-Amp. In particular, it has chosen to use compound op-amps, touting their efficiency and better DC output offset compared to alternatives such as the widely used thermal feedback loop design. It says it chose capacitors and resistors that it thinks work best with these op-amps to produce a “neutral” sound. And it has the circuit board embedded in an aluminum housing for extra insulation and extra protection against external influences.
Design
It’s not just the circuit board that’s wrapped in aluminium: the housings of the CH-Amp’s two units are also made from it – both are 6 inches wide and deep, though the power supply is twice the height of the amp at 2.5 inches. They look very clear cut from the same designer cloth with their impressively solid construction and functional chassis and cleverly stack on top of each other, with the feet of both units giving the boxes about an inch of space from each other (when stacked) and the desk they sit on placed.
Next to the most contemporary-looking desktop alternatives – those from the likes of Chord Electronics or Schiit Audio – the EarMen look like they belong to a past era thanks to the primitive OLED display and amp pin buttons, but we still love their mature, ‘traditional hi-fi’ appearance. The only thing that really bothers us is that the ‘PSU-3’ and ‘CH-Amp’ labels don’t line up when the units are stacked on top of each other. We know, it’s a trifle.
Mind you, that’s compensated by a few nice details: the volume knob clicks subtly when turning, and even more fun is that when you turn the CH-Amp back on (by pressing the volume knob) the volume gradually goes back up to the level it lasted more than a few seconds, rather than startling your ears.
Rechargeable via USB-C, the aluminum plate of a remote control is also a nice weighted thing. The buttons on the top half control the on/off, mute, input select and volume functions of the CH-Amp, while the buttons on the bottom half control a connected Tradutto – useful or useless, depending on whether you have one of course .
EarMen CH-Amp technical specifications
Outputs 6.3 mm, balanced 4.4 mm headphone outputs, RCA pre-out, balanced 4.4 mm pre-outs
Inputs RCA x2, balanced 4.4mm Output level 8V (balanced), 4V (unbalanced)
Impedance 200 ohms (balanced), 100 ohms (unbalanced)
Dimensions (hwd) 3 x 15 x 15 cm (unit), 6 x 15 x 15 cm (power supply)
Weight 550g (unit), 1.59kg (food)
We are fully aware that we are using repetition here for emphasis – ‘functional’ is a word that applies quite broadly to the CH-Amp. Not only are the pair compact enough to call them the ideal size for a desktop application, but they also offer a range of connections that make them fit as an intermediary in a desktop system with only headphones or a wider hi-fi system, and can accommodate headphones that differ greatly in type and impedance level. That’s because their front panel has both (typical) 6.3mm and (niche) balanced 4.4mm headphone outputs, as well as a gain knob that toggles between ‘high’ (1.5W to 32 ohms through the 6.3mm and 3 .8 W into 32 ohms). ohms for balanced) and ‘low’ (260mW into 32 ohms for the 6.3mm and 1W into 32 ohms for balanced) modes.
The only other button on the front panel is a ‘select’ button for switching inputs, of which there are three: two RCAs and a balanced 4.4mm. Perhaps unsurprisingly given its presence as an input and headphone output, the balanced 4.4mm jack is also offered as a pre-out, alongside an RCA option.
Completing that fairly extensive connectivity is a 2x12V DC output required to get power from the power supply via the included cable. Three IC cables are also included in the box as an alternative means of connection for those who also have the EarMen Tradutto DAC and Staccato streamer in their range, with the power supply in this case delivering a total of 12V/1.5A. Also noteworthy on the back panel of the PSU is the voltage switch between 115V and 230V to meet the power requirements of different countries.
Sound
That stack might look clever – especially, we imagine, if you had the full four-component kit – but we’d actually recommend placing them side by side on a sturdy tabletop rather than vertically if you’ve got the space. Do this and the CH-Amp’s sonic presentation sounds more solid and open.
we at Which Hi-Fi? are fairly new to EarMen products and so pleased to hear that the CH-Amp delivers balanced, clear and accurate sound from the get-go while plugging in a range of high quality headphones.
Aldous Harling’s play Old Shell, the CH-Amp can surface decent levels of detail and plot them accurately on a well-mapped canvas. In the song’s opener, the stop and start of each springing piano note and percussive attack are crisp, and when her voice comes through the center of the well-depicted soundstage, it’s clear and intact with her nasal flavor. The bass is controlled and well judged in its presence, while mids and highs shine through clearly.
That clear commitment to an organized and meticulous sound is aided by the fact that the presentation is invitingly large and spaciously open, so you don’t need a lot of volume to feel physically immersed in the sound. In fact, the CH-Amp is never short on power and can reach high volumes without audible distortion.
We find the EarMen CH-Amp’s presentation loses a bit of that openness and spaciousness due to the preamp outputs when we hook it up to our reference system (trying out both unbalanced and balanced routes), sounding smaller and slightly busier than we’d like. as given the price. The tonally balanced, conscientious character we hear through the headphone outputs thankfully remains though.
But during our listening, whether through headphones or system, something is clearly missing, and our suspicions are confirmed when we plug in the Chord Hugo 2. For all its aspirations to be analytical, the EarMen can feel a bit musically disjointed. . We’re playing Kate Bush’s Watching you without me – a go-to track for figuring out a device’s timing – and the EarMen pairing doesn’t quite ‘get’ the interplay of the metronomic drums, double bass pizzicato and synth elements, to the point where this genius composition is criminally bland sounds .
With both its DAC and headphone amplifier now in use, the Hugo 2 better communicates the collaboration between the musical strands, while proving to be more transparent in revealing the timbres of instruments and also more dynamically expressive. The CH-Amp certainly captures where Bush’s elastic voice and smooth instrumentation rise and fall, proving it’s not devoid of dynamic contrast, but the magnitude of the fluctuations in the recording is notably more pronounced due to the headphone amp of the chord. Given the likely cost of the headphone amp stage in the Hugo 2 DAC, that shouldn’t be the case.
Verdict
It leaves us in two minds about the EarMen CH-Amp. On the one hand, it’s a well-featured and nicely built analog unit that sounds maturely clear and accurate, reaching a certain level of analytical status for that; but on the other hand, it lacks the rhythmic and dynamic expression that we believe is essential for music to compel and entertain. In the end, here we have a valiant attempt at a puristic high-end headphone amp – one that’s rarely undertaken these days – but unfortunately not quite one we can defend with confidence.
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