Sound Impressions
Listening to the EarMen CH-Amp Signature was done using the Kennerton Rognir, Audeze LCD-3, AKG 240DF, and ZMF Headphones Eikon headphones, with a brief listen through the Campfire Audio Supermoon.
Sources used were my MacBook Pro and iPhone 16 Pro Max for BT capabilities, and the HiBy R4 for USB-C. The Oppo BDP-83 was tethered to the xDuoo TA-32, then into the CH-Amp Signature via RCA input on the “tube out.”
Summary
Most of the EarMen products I have tried have a vibrant sound with good clarity to them, which allows for micro-details to come forth, but in a collective manner, as opposed to a separative one. The CH-Amp Signature is no different.
With good bass reach driven by the music, I was impressed with the CH-Amp Signature’s ability to accurately portray the low-end with excellent control.
There is a slightly longer decay to me, which allowed the lows to flow effortlessly into the rich, vibrant midrange. The mids come across accurately and with excellent detail as well, making for an excellent connection between the lows and mids.
Vocals leading into the upper end show succinct details and extension without becoming piercing or grating. When called upon, the extension can become a bit sharp, but this allows the sound to extend equally both high and low, tying the ends together.
The only time I felt the CH-Amp Signature felt strained was with 600Ω headphones, such as the AKG 240DFs, using the 6.35mm single-end connection.
This can be overcome using the 4.4mm balanced connection or a powerful DAP. That said, the volume level still satisfied my needs, especially when running the source connection in LO mode.
Bass
The bass came across as strong and controlled, with a slightly longer decay than attack. To me, this made for an excellent extension into the midrange, tying both together.
That extension also gave good foundational aspects to the music, without becoming flabby or bloated.
The control of that low-end might be the best trick the CH-Amp Signature shows. Oftentimes, when extended low, the lack of control comes forth, overshadowing an otherwise good to excellent sonic qualities.
Not so here, as the CH-Amp Signature allowed the note weight to breathe thicker, but with control.
The depth of bass was equal to its note weight qualities, giving off good three-dimensionality to the sound. It was easy to hear when a song had excessive bass built into the sound, and the CH-Amp Signature presented this with excellent control.
Mids
The midrange comes across as well-weighted and with a verve you would associate with EarMen products, to me. In other words, that means there is very good to excellent energy across the low to high midrange, and a sound that is slightly pushed up and forward.
Individual parts can be discerned with ease as you move in and out of the presentation, or up and down the frequency range. Transparency in the note quality comes across as superb and very accurate.
There is no feeling of artificiality in the sound, with an organic rolling character that exudes accuracy and musicality in the same vein.
Again, the micro-details associated with vocals or softer instruments lend to that accuracy, with a textural presence that exudes quality. The vibrant character of the brand’s sound shows itself with accuracy and detail rolled into a musical mid-section that is very, very good.
While I wouldn’t state that the midrange dominates the sound, it certainly ties the whole thing together nicely.
Treble
The treble region provides very good extension, without ever becoming buzzy or strident. I did find music that shows a high level of energy in the upper regions does promote itself on the CH-Amp Signature, too.
There is no hiding from that, but this is not for a lack of aesthetics, but rather the quality with which the CH-Amp Signature comes across.
Micro detail shows itself again, with the softer, accurate sound coming from instruments that may get lost in some sonic qualities. There is an airiness to the top end that shows off in style, the ability to add lift as well as keep the note weight of the mid to upper treble.
Sometimes this is not the case, as extended highs can become thin or wispy. But not here, the CH-Amp Signature provides the listener with excellent extension and accuracy, again coupled together to make for a very musical crispness to it, that exudes quality.
Staging & Imaging
The manner in which the low end melds with the midrange and the upper midrange couples to the highs, giving the CH-Amp Signature a cubic quality to the soundstage. Not identically-dimensioned, but spacious enough to allow all parts to function as a whole.
The midrange does push the height up a slight bit, but the width extends beyond the ears, and the depth matches that width synergistically.
I would say that the treble region helps the extended height, but provides a complementary aspect to the midrange, which, if left unchecked, could make for an unrealistic height “advantage.”
The combination of these makes for excellent layering and imaging. Instruments flow into the frequency region where they should be.
The depth of those instruments on stage allows for very good imaging, with the left-right aspect giving a good representation of where each part lies, whether in studio or live on stage.
I never felt that the CH-Amp Signature struggled with complicated pieces, either. Due to the accuracy of presentation and layering, each part acted as part of the whole, again representing the musical nature presented in each genre.
Synergy
Efficiency
Even using the most sensitive IEMs I own, the Campfire Audio Supermoon, the background was almost completely black.
On the IEM setting, the noise level was kept to a minimum while presenting a highly musical response with a black background. A slight hissing was heard between songs, but once the music started, the CH-Amp Signature became silent.
The CH-Amp Signature never felt out of control, even when using the more demanding AKGs, which bodes well for use with harder-to-drive headphones of that sort.
Power
As mentioned above, the only “lacking aspect” concerning power was when using the 600Ω AKG 240DFs, through the 6.35mm single-end jack.
While I could reach levels that satiated my desired listening level, I came close to max (26 out of 30 on the volume) to attain that, even on full volume LO. At full volume, I could listen, but it was beyond my comfort level. Some may be able to reach that full-volume level, but I could not.
All of the other listening headphones were able to be powered through the 4.4mm balanced jack with ease.
I never had to move past 22/30 to attain an adequate listening volume. Combined with a source input that has plenty of juice, though, the CH-Amp Signature could readily drive anything I sent its way.
Pairings
The Audeze LCD-3 is known for excellent bass response, and that planar sound of smooth midrange and good treble extension.
The CH-Amp Signature paired well with the Audeze, adding a bit better response to the upper regions, without losing the levels of detail down low. The pairing together could be played loud or soft; it did not matter; a smooth level of clarity was heard across the spectrum.
The ZMF Eikon (300Ω) functioned similarly but needed more power to attain the same listening enjoyment.
The openness of the Audeze was lost a bit, but the CH-Amp Signature helped keep the Eikon lighter and airier in response to raising the volume. Bass extension was not as low, but was kept under excellent control, even at loud levels.
The Kennerton Rognir was the first headphone used, and came across as excellent, but the overall tendency of the Rognir to have a more punctuating midrange could not be completely covered by the CH-Amp Signature. Still present, I had to keep the volume level lower, so it would not become piercing.
The AKGs were probably the most fun-sounding of the quartet, even with the additional volume level needed. They are old, but still a fabulous set of headphones, and complement the CH-Amp Signature with aplomb.
Pairing the old with the new was a treat as the low-end was tight and controlled, while the midrange was probably the highlight of using the pair together.
Listening to any of the sources was excellent across the board, with BT showing how far it has come technology-wise. The majority of time was spent streaming through the HiBy R4, and I appreciated the uplift in quality the CH-Amp Signature provided.
