CH-Amp Design, Build quality
The EarMen CH-Amp is CNC’d from a solid block of aluminum and it as a result has a full aluminum chassis. This – as we all know – makes it extremely durable and robust. The PCB is embedded in a solid aluminum housing, giving the board greater protection inside the housing and additional insulation from external influences.
With its compact design, the EarMen CH-Amp (as well as the full stack) fits to any environment, any system or home. The CH-Amp measures only 150x30x150 mm or 5,9″xl,18″x5,9″ and it weighs only 550 gr / l,2llbs. The PSU-3 measures 150x60x150 mm / 5,9″x2,36″x5,9″ and it weighs 1.590 gr / 3,52 Ibs. The full EarMen stack with all 4 units on top of each other measures 17cm / 6,67” from top to bottom (Staccato antenna not included).
The build quality is perfect and identical to the one of Tradutto, which we reviewed already. All units feel solid and there’s enough weight, so they don’t move around on your desk when connecting/disconnecting cables and headphones. All buttons feel good when clicking and turning them and all the inputs and outputs are solid. Just make sure not to scratch the front plate when inserting headphones.
On the top of the unit, you have the CH-AMP name engraved in the enclosure. There’s nothing to see on the sides as all the action is on the front and back.
The front panel lay-out from left to right is the following:
Single Ended 6.35mm headphone output – 4.4mm balanced headphone output – OLED display (3.5cm) – Input selector – Remote receiver – gain switch – On/Off & Volume knob/control – EarMen logo.
The back of the unit is very busy and you here from left to right have:
Power Supply input – Balanced 4.4mm PRE-Out – RCA Single Ended PRE-Out – Line 2 RCA SE Input – Line 1 RCA SE Input – 4.4mm Balanced Input.
Unless differently mentioned, we are using the full balanced connections & setup in this review.
I could copy/paste the full specs from EarMen’s website, but as the specs lay-out on their site is nicely done, I will just link to them here. Just scroll to the bottom of the page.
Sound – Intro
You can perfectly use the CH-Amp and PSU-3 with any DAC or source of your choice. I, for this review, had it mostly connected to the Tradutto DAC, but I have also used the dCS LINA DAC as source. Next to that I have used the BT connection directly from my phone to the Staccato and Tradutto (you can choose).
As mentioned before, this review is based on an all-balanced setup using the 4.4mm connections on the back and the 4.4mm output on the front. Sources were Tidal via ROON, Spotify (via the EarMen app and the Staccato) and local files via ROON.
The mini screen on the CH-Amp shows if you’re using the amp in SE or Balanced mode, what volume you have the unit set on, which gain setting is activated and you also have a L/R dB VU meter. In Pre-amp mode the gain setting “LOW/HIGH” gets replaced by the PRE mention. With normal to drive headphones and a normal listening volume, the dB meters won’t blink a lot, it’s especially in PRE mode when you will see the L and R channel dancing on the LCD.
When you have a headphone plugged in, the unit will always prioritize this output. When you disconnect your headphone, your music will be automatically paused, and the CH-Amp will switch to the PRE setting. The volume will be automatically r(e)set to 0, and the same goes for switching from PRE to AMP mode. I think is a great feature and my ears appreciate it.
I first listened to the CH-AMP in the full stack configuration at the High-End Munich show. I remember EarMen was demoing them with the Meze Audio ELITE and I was seriously impressed by the depth, the layering, the overall timbre and especially the great dynamics from this little stack. I in fact shouldn’t be calling it little as the sound this setup produces, is big. For the part on sound we have used a series of headphones such as the Elite, the Susvara, the HD800S and many more. We will have a dedicated chapter on “pairings” later in this article.
The CH-Amp is small in size, but it surely delivers a high-end sound. The sound quality of this unit is impressive, and if you’ve have read any of the show reports lately, you’ll know many who demoed this unit fully agree to that.
The EarMen CH-Amp has a more neutral tuning, with a dynamic, energetic and lively character. The CH-Amp is fast, precise and dead silent at all times. Sound stage-wise the CH-Amp also delivers, it’s very good in the width and good in depth but it’s not the most extended amp ever in this area, nor does it pretend to be. The layering from top to bottom is good.
The CH-Amp has a spacious and airy feeling, but what really impresses is how effortless the CH-Amp delivers everything. It doesn’t matter if it’s a dynamic or Orthodynamic driver, fast or slow paced music, etc. The CH-Amp makes it look like easy. But it’s more than that, it isn’t just easy, it always is at a very high technical level and presented in an engaging, and very musical way.
The CH-Amp doesn’t really add anything to the sound of your headphone. It’s a transparent amplifier that will show you the strengths of your headphone in use. Its precision is good. The CH-Amp isn’t the boring analytical type of amp. We here on top of that precision get liveliness combined with a musical layer that will make it hard not to enjoy every second of this amplifier’s playtime. There maybe is a bit of margin for improvement for what decay and note extension is concerned, but the dynamics, liveliness and musicality largely make up for that. You never have the feeling you’re missing out on something.
Regarding body and weight, this amplifier is also more neutral from top to bottom. There’s enough weight and impact to make things engaging/enjoyable and it’s all in a natural and realistic way. The bass quality here is more important than the quantity, though there always is enough of it. Bass is spacious and airy with good depth and layering. Sub bass presence of course depends on your headphone in use. While the bass part is good, it really are the mids where the CH-Amp shines. A natural, vibrant presentation, combined with an excellent level of technicalities and a gorgeous vocal presentation. The mids are rich in detail, engaging and very musical. For what body and presence are concerned, they perfectly connect to the bass and treble. That means, it’s somewhat lighter in presence, but all in a natural and non-boosted way. The treble section is lively, energetic and precise. It’s spacious and airy and it never becomes sharp or too forward sounding.
All-in-all the CH-Amp really delivers when it comes to sound. The EarMen engineers have done a great job building a compact, powerful, dynamic, precise and very musical amplifier.
Balanced vs Single ended headphone output
For this test we used the CH-Amp in balanced config with the Tradutto DAC and the Meze Audio ELITE headphone. You can connect a headphone in SE and Balanced mode at the same time.
The first thing you will notice when switching from balanced to single ended, is that you will need to increase the volume to stay at the same volume level (watch out when switching back to balanced). In balanced mode you get better dynamics, power and energy, next to more body and bass impact. In SE mode you get an even stronger neutral and simple presentation where the liveliness is not as present. The technical level is good in both modes, but the balanced output is more expressive, where the SE one is flatter, dryer sounding. You could describe the SE output as neutral and flat, and the balanced output as more dynamic, full, and lively.
For me the balanced output is the one to go for in most cases, though I – as you will read in a minute – love the DT1990 PRO in single ended mode.
The part on sound continues on the third page. Click here or use the jumps below.
Page 1: EarMen, CH-Amp, PSU-3
Page 2: Ch-Amp Design, Build quality, Lay-out, specs, Sound Pt. 1
Page 3: Sound Pt. 2, Comparisons, End words