In my world timbre is front and center as it is one of the three primary factors that elicit an emotional response to music: Timbre (harmonics), Rhythm (timing) & Dynamics. In short, I love being "caressed" by the timbre of the Hermanos Gutierrez oscillating guitar strings! I think/feel that my Holo Spring3 KTE DAC and Cayin H3A3 Amp with the AO might just be just the sonic magic I'm hoping for.
I'm a neophyte to the Atrium and far from an authoritative source on the matter but, I think you will be quite pleased. Have only completed 200 of the 300 hour recommended burn-in phase as well. Keep in mind I'm using the solid state Nitsch Pietus Maximus w/ built-in ESS chip and cannot speak to a tube/r2r combo. However, gut reactions have value.
Out the box, the timbre is great, as expected. Sonic textures showed up earlier than I expected too. Everything else you (and I) value takes a lot of time to develop. These changes to are, in some cases, quite subtle but make all the difference.
Even after 100 hours, the fluidity was a bit rough. Had a bunch of nervous energy. Not so much from the frequency response, but more from the time domain and transients. It presented plenty of fancy 'hi-fi' goodness but, I didn't find it as 'musical' as I wanted due to this. Also, the imaging/soundstage was flat and overly defined whereas I prefer more diffusion. And where is the bass? All in all, it sounded a little too stereotypically 'hi-fi' for my taste. Too 'uptight' to be more specific. Interestingly, I found details more forward at this stage as well.
At the 200 hour mark the AO is much improved with regard to timing, fluidity, overtones, cohesion, frequency extension, and staging. Pitch differentiation on bass notes is also great, which really helps the overall sense of timbral continuity. Though, I will say, tone is a bit warmer/richer now than out of the box. Pads swaps may correct this if one prefers a more 'transparent' tone. Currently I find it a pleasant balance between absolute timbral accuracy and a more romantic analog sound. But, I see myself pad swapping in the future according to mood. The flexibility that pads, meshes, and cables offer to shift the sound was a big selling point. At this level of resolution minor warts, or even just slight differences in preference, become major.
Dynamics are also as advertised after 200 hours. Very nice clarity from low level sounds contrasting well with louder, more overt instrumentation. Impact is better than I expected and helps reinforce the dynamics. Coming from the E-Mu Teak, I had concerns that the punchiness one gets from a closed back headphone might be a letdown on the far more open backed Atrium; it is not. I'll admit it, at the 100 hr. mark, I thought I should have gone for the Atrium Closed instead. That is no longer the case.
Image and stage are also now more diffuse and enveloping; more natural to my ears. If your preference is to be 'swimming' in tones you will really like these. The atmospheric sense I'm getting from not just natural instruments like guitars that have reverb, but also Fender-Rhodes pianos and vintage analog synths, is kinda awesome. Your Cayin/Holo combo should only accentuate this.
I'm digging the Atrium Open thus far. The presentation is pretty neat, for lack of a better term. Its quite detailed but, not 'showy' about it. If you want to focus on it, you certainly can. Instead, my attention is naturally drawn towards the overall atmosphere and mood due to how good the timbre is. Being a new toy, I thought I would focus more on all the little things the headphone is doing, instead its forcing me to actually focus on the music. Strange concept, I know.
, I allowed myself 10 seconds of listening.
