http://www.head-fi.org/t/687944/999-calyx-m-with-dxd-dsd-64gb-sd-sd-storage/2580#post_10528030:
So to complete my DAP comparisons with the Calyx M, I went down to one of the local store that has a demo DX90 unit available for auditioning to get a feel of how DX90 "would" compare against Calyx M.
The 1st track I loaded to test is redbook CD quality 44/16 FLAC quality music -
"Unite" by Misawa Sachika, 2nd ending song from the Accel World anime (may take a while to load the buffer for streaming). It has a very good mix of modern pop song style with strong female vocal as well as a multitude of instrument sounds in the background including a lot of cymbals to test out the entire audio frequency range.
DX90 vs AK240 (on 1plus2):
Obviously DX90 is not going to stand up to the AK240 toe-to-toe on SQ, so I would just give a brief comparison how DX90 fares. The soundstage is smaller than AK240, and the DX90's sound quality has a high level of digitized feel to it relative to AK240. Everything seems more closed up on the DX90 and flatter (less depth) than the AK240. This makes the vocal seem to be on the same plane/dimension as the other background instruments. Separation is there but just not that big of a 3D soundstage. The frequent cymbal sounds are also less natural and felt like it is forced out of the DX90 as compared to the AK240 which is buttery smooth/natural. On parts of the track which has more complex mix of instruments kicking in at the same time, the DX90 sounded less coherent (probably partly due to the weaker soundstage; everything sounded mashed up together and come at you all at once). I tested other high quality tracks and get the same feeling. I detected only one issue with the DX90 on one of my DXD 352.8 kHz track -
Vivaldi: Recitative and Aria from Cantata RV 679, "Che giova il sospirar, povero core" Tone Wik & Barokkanerne (period instruments) from
2L. There is a very loud constant hissing background sound during playback which is not heard on my PC or on the AK240. It could be a bug. The good thing about the DX90 is that it is quite transparent and neutral and felt much more balanced to me than the SQ I heard from Calyx M. I cannot expect it to perform on par with a $2,400 AK240 at its price point but it really performs surprisingly well for a sub-$500 DAP. So just to satisfy my curiousity, I A-B the DX90 against my AK120 which I also brought along.
DX90 vs AK120 (on 1plus2):
This is going to be an interesting comparison. My short conclusion is that DX90 performs near to 80-90% of AK120. IMO it is still slightly behind the AK120 in terms of sound quality, but the gap is not huge. Considering the DX90 costs less than half of the AK120, I think it is a job well-done by iBasso (they just need to fix the software bugs, improve the UI and enable USB DAC feature). On most tracks DX90 sounds just as good and enjoyable as the AK120. The AK120 sounded slightly more forward/warm than the DX90, but not substantial enough to make too big a difference in their signatures. AK120 tends to have a more smooth feel to its SQ compared to the DX90 which is a little more analytical/cold (or digital to me). For e.g. 36-42 secs into
Hotel California where the cymbals clash with the electric guitar sound reverberating around behind you, the DX90 reproduction sounded less musical and smooth compared to AK120/240. Both have roughly about the same level of black background and the UI on the DX90 feels more smooth and responsive than my AK120.
DX90 vs Calyx M (on 1plus2) "Extrapolated":
Since both demo units are from different local stores, I have to audition them separately against my AK DAPs and extrapolate to make a comparison. So take my feedback here lightly, but one thing I am very certain about the Calyx M is that its sound signature is much thicker than the DX90, AK120 and AK240. I do not get the same shock feeling when transiting from AK120/240 to DX90 as when transiting from AK120/240 to Calyx M. My conclusion here is that Calyx M sounds quite different from DX90 in terms of signature, but both are equally good on clarity using AK120 as a midway benchmark. DX90 is definitely more of a forward/closer soundstage and flatter/more neutral frequency response across the entire spectrum. Calyx M is more of a heavy bottom and unevenly aggressive frequency response. Soundstage for both is similar. Another side note which I forgot to mention previously is that both seem to cut off the front 1-2 sec of the first audio track I tried to play. Subsequent tracks did not have this issue. Seems like X5 also has a similar problem. No idea what is up with all these cut offs.
So here is my take on the Calyx M thus far. I will try to go back to listen to the Calyx M for a 2nd round to re-confirm what I have heard.