I received my Audio-gd Compass 2 yesterday (default build with the 2 free TCXOs... not sure what those are supposed to change to the sound, but hey: they were free!), and I thought I would publish a summary of first impressions I got with the unit.
While reading this post, keep in mind that I am still a neophyte audiophile and as such, I will try to do my best to describe what I hear in my own words. I am looking forward to reading about what other owners think about this unit (or comparable Audio-gd units) and suggestions as of things to try to improve the sound experience I am getting. Also, feel free to correct me if what I describe is inaccurate or if some of my manipulations don't make sense (still learning )
I upgraded from my first amp and DAC, which were the Fiio E9 and E7 and I am doing all of my listening with Sennheiser HD650s, which I love. It is also important to note that while I enjoy all kinds of music, I mostly listen to electronic based music. My music source is my Macbook Pro Early 2011, which sports an optical output on top of the usual USB and headphone out connectors.
I did my first listening of the new Deadmau5 album downloaded from iTunes (256 kbps AAC, 44.1 kHz) through the optical output. I tried listening to the tracks through iTunes and Audirvana Free and did not hear noticeable difference between the two. I was somewhat shocked as to the extra details I was hearing that I never realized were there before. I am hearing subtle reverberation in between the kicks that I never heard before, which is great. Higher frequency details are clearer than what I'm used to while not being piercing at all. I am usually quite sensible to high frequencies and hate it when they are too loud and this is not the case with this unit. One thing that I find weird though is it seems to me that Mid-higher range seems to be overwhelming compared to the bass, which is normally the most present frequency range of this kind of music. The level of this frequency range seems too loud and it makes details not as clear in this frequency range as with the rest of the spectrum. Not sure I like that too much, but I should continue my listening experience to see if this is track related or not. Finally, the bass seems to be a bit lacking for my taste. Upper bass range is really detailed, but I miss the lower part of the bass range, maybe sub-bass. This becomes more obvious when I listen to some dubstep. As I start to play the first Rusko album, which has some of the bassiest content I know, I am a little disappointed as the mid section again seems to overshadow the bass section. Changing to USB, I did not notice a lot of sound quality difference, but I sometimes hear pops when doing the slightest bit of work on the computer (scrolling up and down on a webpage seems enough to trigger them) which I do not like at all. Maybe it could be because of the cable they packaged with the unit, or maybe it comes from the laptop itself. I should try to play from another USB source (either a Windows PC or maybe the iPad with the camera connection kit, if it's compatible... I have to verify).
The first time I tried the unit (yesterday), I was noticing a lot of digital artefacts while listening to my tracks compared to what I was used to (only in subtle, low-level details though). Maybe it has to do with the quality of my tracks, which mostly are iTunes 256kbps AAC, but some are lower bitrates MP3s (nothing below 160 kbps, some 192 kbps and some ~256 kbps variable bitrate). The more I listen though, the less I get this feeling. Maybe the unit has started to "open up" like I am getting used to read in this forum... or maybe my ears are getting used to it...?
Finally, I tried listening to tracks by connecting the unit through the headphone out of the laptop in the line in of the unit. In this case, the bass seem a little bit more present, the highs a little bit less clear, and the mids still a little overpowered, but the whole seem a little more balanced (in my opinion).
I am going to let them warm up 24/7 and continue my listening experience for the next days/weeks and post back if my experience with the Compass 2 change. Right now, I am impressed with some aspects of it (the level of details of the playback, the clarity of the highs), but quite underwhelmed by some other aspects of it (popping sounds with USB, overpowering mid section).
If any of you have suggestions as to some things I could try to fix the issues I'm hearing with the unit, please don't hesitate.
- Would changing the ES9018 for the dual WM8741 help improve the sound I get from the DAC?
- Should I fiddle with the sampling rate and bit per sample in OS X Audio and Midi settings?
- Should I use a third party software sound processing application (I own Joesoft Hear, but I did not use it for those listening tests)?
- What unit input/laptop output should have the best quality?
- Should I use low/high gain setting on the unit? Does it make a difference?
All suggestions or comments are welcome, good or bad (suggestions must be good... only comments can be bad )!
Thank you for reading this.
EDIT: I just installed the Moon OPA that I had ordered with the unit and now, I find the sound when connecting the headphone out of my laptop to the line in of the Compass 2 much better! The bass really come out, everything is still really clear, yet warmer and more pleasant to listen to. Less analytical I would say. The only problem is that OPA only affects the line input, not the DAC signal paths. This is a bummer, since I bought this unit over a standalone headphone amp because I wanted to bypass the DAC of my laptop, thinking I would get better sound. I will continue my listening and report any changes later on.
Edited by franmon83 - 10/13/12 at 1:30pm