Nice work. I'm not a 2132/2134 fan -- they sound good initially but are a bit mushy-sounding and lacking in dynamics. I'd rather have the NE5532/5534 in there if not the 627s. I do wonder about those Muses opamps though.

Thanks to you both for the kind words. I believe all 2132 and 2134 chips come from the same wafer, it's just that the best ones are labelled 2132P and the worst 2134PA.
Anyway, I opened my DP1 a bit and it's using 2*OPA627AP for buffering and 4*OPA2132P as I/V. Scott Wurcer(designer of AD797) stated clearly on the diyaudio forum that opamps don't have a "sound" of their own. I'm certainly not hearing the mushy sound of OPA2132P used a stereo PCM1793 LPF in the DP1 for that matter.
But yes, I guess four genuine OPA627AU soldered onto DIP8 adapters would do wonders in the headamp section of the ONE

another considerable upgrade!

Well written ....well done

Awesomely done Leeperry, great review mate
I've rolled quite few opamp combos and there is absolutely none better than the Muses, so much so I did a A>B test with the Fostex HP-A8C using the TH900s and the Asus E1 Muses to my ears SQ alone SlayeRd it

I think this is going to be my next upgrade seems very affordable

What a great review! Thanks a lot! I'm gonna get me one...

Great review, congrads on being featured on the front page! Looking to upgrade my E1 to muses now, cheers!

Great review! I am really glad a major company like Asus got into this business! Some of the prices in audio are absolutely RIDICULOUS. That is because no major company has invested seriously in r&d, nor has it industrialized this domain because the market is to small for them. I hope the market grows and companies like Asus would get into this business seriously!

That will be a major hit to companies with absolutely ridiculous prices. Sometimes when I look inside an amplifier/ dac over 3k I get pissed off. Compared to graphic cards for example, the technology in audio...is far.. far... far less advanced & complex.

Awesome.
I have checked out all the links.
They are great.
Thanks..............

Nice review thanks. As a new audio user this product seems to focused on new users and experts like your self’s with experience and such. As a new user I ordered my first expensive cans ever..The T5p’s and to start of the Fiio E12 and for a DAC the Fiio E10..Here is my question I would very much appreciate it if someone could point me in the right direction.The 6Moon review is Is stellar to say the least. After reading it I wanted to run to the stores (not available in Holland yet).But after reading the review from innerfidelity I got scared I mean I like my base and good impact..But also detail when listening to classic and focal music. So what am I to do???The thing is this , I really don’t understand anymore. Let me give you my current dilemma.I just ordered the Fiio E10 dac..Lots of reviews where ok.. good components and ok SQ.But then on the last day when it is shipped. I read this Basically stating that’s it’s no good. The parts are ok , but the way it has been used is flawed.Same thing with the xonar essence one Muse. The one says it’s the best thing ever.The other says it good But watch out It can sound terrible if paired with the wrong set of cans. Now as a newbie I understand that pairing with the right headset is crucial.This is kind of logical even for me. But as a starting audio guy I wanted a good all in one option to get my feet wet. And start of with a good all in one..So what do I do now ? My T5p’s will be coming in soon (I hope) the Fiio E12 and Fiio E10 (tomorrow).Do I send back the Fiio E10 and wait until the Muse comes out and spend the €500 ore a bit more when it comes out..? the E10 is €90. I don’t mind spending more but I want something that sounds good with Beyerdynamic and maybe HifiMan later on..

Can you believe it I emaild a store about the Muse edition and he told me that they will get in next week. For the price of €800 that’s $1030. I could order it and have 14 days without shipping back 2 days to listen to it and determine if I like it or not..I think 50-100 hours of burn in would be good? So 4 to 5 days of burn in..Still it’s a lot of money Much more than my first €90 for a dac Fiio E10… As always I will wait your responses here.. 2e factor is that the prices will drop if I wait a month or 3 ?? Don’t know if I can wait that long hahaha..If I look at the “ Asus xonar essence” the price is stable at €366 started 2 years ago at €377.So it would probably not drop to much..even if I waited..will ask the store if they can give me 10% off or something like that .because I’m a well known customor..

well this is an active review ?? Dead silence..i feel like i'm in the movie 2010 Space Odyssey staring at the big Head-fi monolith ahahha!
There is no reflection just emptiness all around me...no sound just silence..
No matter as all things audio , one must do there one research so , i will be getting the Asus Muse and testing it my self..
Take care ..Adios amigos..

smpie, if you want more activity, there's far more information on the CEBIT Essence One page: http://www.head-fi.org/t/542563/asus-essence-one-headphone-amp-dac-cebit-2011

smpie, there's far more activity and information here:
http://www.head-fi.org/t/542563/asus-essence-one-headphone-amp-dac-cebit-2011

To clear things up, the innerfidelity review is not using a retail Muses unit with the improved PCB providing a more accurate pot and a headamp gain switch.....it's a vanilla standard ONE populated with 6X Muses opamps.
Many people have claimed to hear drastic SQ differences between those different PCB revisions and I can certainly confirm that the real genuine retail Muses ONE sounds quite different depending on the headamp gain switch position.
Yep, this review form is nice and all but it's really not ideal for discussion so you may wanna post in the aforementioned discussion thread.

Great review!
I just bought the Muses edition myself and paired it with my (unmodded) Denon AH-D7k. I was somewhat surprised at first; the soundstage was verry small, not as high resolution as i expected and the high frequencies are too high - leading to listening fatigue, the "Chime Tiger" was chained. Compared to my listeningexperience with these cans and a Creative Xtreme Music (which worked extremely well, that card is severely underestimated), this was a huge disapointment. Either I had to get used to it (like a new hairstyle), get a different headphone that matches better OR I could try to use the "RCA out" in the back instead of the dedicated 6,5 mm jack at the front. I remembered that when the software on my Xtreme music had recogniced that I used headphones, the sounds suddenly became verry restricted and dull, it might be the same here... And Right as rain, suddenly the Chime Tiger was free, roaring and wreaking havoc, Suddenly the soundstage was widdened, the resolution seemed increased and the highs was not as fatigue inducing PLUS the base started pumping.
I dont know if this works for all Headphones, but I recommend that you try it, it really changed my view of this item, from a disapointment to satisfaction. (RCA -> 3,5mm -> 6,5mm conversion though :/ )

That actually makes a lot of difference for me! My grados sounded shrill on the headphone out, and when I used the speaker amp headphone out, it took the shrillness out. This wasn't psychological either, it made a pretty huge difference in what I could tolerate, fatigue-wise out of those headphones. I confirmed it with a pair of sennheisers, but it didn't make as much a difference since the highs are already toned down on those.

Well, those denon's come with very low impedance and high sensitivity so you really want to crack open your Muses ONE and switch the headamp gain to its low position IMHO.
These phones are meant to be driven effortlessly from any DAP so indeed excessive headamping might very well end up making things (a lot) worse...also some ppl like the less percussive sound of a vanilla line-out when others will prefer the high gain position of the ONE because it sounds "thicker" so to speak.
Also, all headphones will sound "shrill" to some extent due to physiological ear resonances so I would strongly advise to give this tutorial a whirl: http://www.head-fi.org/t/413900/

Will definitely check out the EQ tutorial