EarMen CH-Amp headphone amplifier
CH-Amp or ch-ump?
• Crisp, open and precise-sounding
• Solid, traditional casework
• Good spread of analogue connections
• Beaten for dynamic expression
• Primitive on-unit buttons $2,650
EarMen was created as an arm and sister brand to respected European manufacturer Auris Audio by its founder Milomir “Miki” Trosic to serve a specific purpose: enhance portable listening. Unlike Auris Audio’s catalogue, which isn’t afraid of the super high-end (as its 24k gold Hawk tonearm and high-spec, hand-crafted range of amplifiers demonstrate), EarMen’s was to be filled with small, affordable, battery-powered and USB DAC/headphone amplifiers designed to give phones, computers and other portable/desktop devices the sonic boost they so desperately needed. But then in late 2021, once EarMen had a nice line of such units under its belt, Trosic couldn’t help himself; 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 analogue headphone amplifier that is under scrutiny here. Indeed, EarMen has pushed its formative ambitions past the portable and affordable to produce a stack of high-end head-fi separates.
DESIGN & IN USE
The CH-Amp is a fully balanced headphone amp with a built-in pre-amp and comes with a separate (supplied) linear power supply unit called the PSU-3. The ‘fully balanced’ design means that as well as incoming balanced signals being outputted intact (albeit amplified), signals that come through its single-ended RCA inputs are converted to balanced ones, supposedly with the positive and negative signals perfectly in phase. The external power supply, meanwhile, has been developed to offer clean power with “minimal noise” to its headphone amplifier partner, and to the Tradutto and Staccato as well if required.
EarMen has used its experience in headphone amplifier design, and no doubt that of Auris Audio’s, to develop the CH-Amp. Specifically, it has chosen to use composite op-amps, praising their efficiency and better DC output-offset compared to alternatives such as the commonly used thermal feedback loop design. It says it has chosen capacitors and resistors it believes work best with these op-amps to produce a “neutral” sound. And it has embedded the circuit board in an aluminium housing for added insulation and extra protection against external influences, too.
It isn’t just the circuit board that is wrapped in aluminium, either: the casework for the CH-Amp’s two units is too — both 15cm wide and deep, albeit the power supply is double the height of the amplifier at 6cm. They look very clearly cut from the same design cloth with their impressively solid build and functional chassis and do stack smartly together, with both unit’s feet giving the boxes a centimetre or so’s
clearance from one another (if stacked) and the desk onto which they’re placed. Next to the most contemporary-looking desktop duos — those from the likes of Chord Electronics or Schiit Audio, for example — the EarMens do look as though they belong to a previous era due to the amp’s primitive OLED display and pin buttons, but I was quite taken by their mature ‘traditional hi-fi’ look. The only thing that really bothered me was the ‘PSU-3’ and ‘CH-Amp’ labels not lining up with one another when the units are stacked.
Mind you, that is oset by a couple of nice touches: the volume dial clicks subtly upon rotation, and even more rewarding is that when you unmute the CH-Amp (by pushing in the volume dial) the volume gradually increases back to the level it was at over a few seconds rather than just startle your ears.
Chargeable via USB-C, the aluminium slab of remote control is a nicely weighted thing, too.
The top half’s buttons control the CH-Amp’s power, mute, input selection and volume, while the bottom half’s buttons control a connected Tradutto — handy or futile depending on whether you own one, of course.
Fully aware I’m using repetition for emphasis here, ‘functional’ is a word that applies rather broadly to the CH-Amp. Not only are the pair compact enough to call ideal sizes for a desktop, but they also oer a platter of connections that make them fit either as a middleman in a headphones-only desktop system or a wider hi-fi system, and can accommodate headphones that vary widely in type and impedance level. That’s because their front panel features both (typical) 6.3mm and (niche) balanced 4.4mm headphone outputs, as well as a gain button that switches between ‘high’ (1.5W into 32 ohms through the 6.3mm, and 3.8W into 32 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 is a ‘select’ button for switching inputs, of which there are three — two RCAs and a balanced 4.4mm. Perhaps unsurprisingly considering its presence as an input and headphone output, the balanced 4.4mm connection is also oered as a pre-out, alongside an RCA option.
That rather generous, comprehensive connectivity is completed by a 2x12V DC outlet necessary to receive power from the power supply via the supplied cable. Three IC cables are also provided in the box as an alternative means of connection for those who also own the EarMen Tradutto DAC and Staccato streamer in the range, with the power supply able to deliver a total of 12V/1.5A in this instance. Also noteworthy on the PSU3’s rear panel is the voltage switch between 115V and 230V to accommodate dierent countries’ power requirements.
That stack may look smart — especially, I would imagine, if you had the full four-component set — but I would actually recommend putting them sideby-side on a solid tabletop, as opposed to vertically, if you have the space. Do so and the CH-Amp’s sonic presentation will sound more solid and open.
Considering the EarMen CH-Amp is the first product of the company’s that I have properly been acquainted with, I was glad to hear it deliver an even-handed, crisp and precise sound from the o as I plugged in an assortment of high-end headphones. I should say that it was upon switching headphones for dierent listening sessions that I appreciated that the CH-Amp’s volume level returns to zero and the gain to ‘low mode’ every time it’s powered up, presumably to avoid the owner being startled by their previous session’s volume level or indeed caught out by a dierent pair of headphones’ impedance level. Some may find this annoying if they are only plugging in the same pair every time, but I personally like this safeguard.
Playing Aldous Harling’s Old Peel, the CH-Amp capably surfaces decent detail levels and plots them precisely on a well-mapped canvas. In the song’s opener, the stop and start of each springy piano note and percussive strike are crisp, and when her vocal comes through the middle of the well-imaged soundstage, it’s clear and intact with her nasally flavour. Bass is controlled and well-judged in its presence, while mids and highs shine through with apt clarity.
That clear striving for an organised and meticulous sound is helped by the fact its presentation is invitingly big and spacious open, so you don’t need lots of volume to feel physically immersed in the sound. In fact, the CH-Amp never feels short of power and can reach higher volumes than you’d probably ever need, without distortion audibly creeping in.
I would actually recommend putting them side-by-side on a solid tabletop, as opposed to vertically
Perfume Genius’s Otherside ballad is a similarly positive advert for the amplifier’s big, bold and alluring character, with the glitterbomb of shiny, shimmery synths that explodes out of nowhere from the delicate piano ballad filling the soundstage to a hair-raising eect. Its delivery certainly has the power and openness to get across a sense of occasion.
The EarMen CH-Amp’s presentation does tend to lose a bit of that openness and spaciousness through the preamp outputs
(both through unbalanced and balanced routes), sounding slightly smaller and a little more congested, but the tonally balanced, conscientious character that I heard through the headphone outputs thankfully remains.
However, for all of its ambitions to be analytical — ambitions it largely achieves, at that — the amp isn’t the most dynamically or rhythmically expressive bit of kit I’ve heard. Playing Kate Bush’s Watching Me Watching
You (one of my go-to tracks for sussing out a piece of equipment’s timing), the EarMen pairing doesn’t quite ‘get’ the interplay of the metronomic drums, double bass pizzicato and synth elements as well as it might.
Out of two pairings — the first, the Chord Hugo 2 DAC feeding the EarMen CH-Amp, the second the Chord Hugo 2 DAC and headphone amplifier used together — it’s the latter that better communicates the cooperation between the musical strands and gets under the textures and timbres of instruments. That said, the Chord Hugo 2 is somewhat special and does this to every other piece of similarly priced equipment I’ve put up against it so far. And the CH-Amp is hardly bereft of dynamic contrast, easily able to convey where Bush’s elastic vocal and the supple instrumentation rises and falls.
So no, you aren’t getting benchmark rhythmic and dynamic expression at this level here. But what you are getting is plenty — a well-featured and nicely built analogue unit that sounds maturely crisp and precise and achieves some level of analytical status for that.
The Earmen CH-Amp is a brave attempt at a purist high-end headphone amplifier — one which is rarely undertaken these days — and for that EarMen should be credited.