[ctm]

I did a few searches and could not find a post detailing a direct comparison of the DAC performances of these two units.  OK, some of you may be shaking your heads and asking something like, "Who cares?"
 
I admit the question is more academic and disregards important factors like practicality and value.  So first let me clarify that I am aware that this is not really an apples to apples comparison and I realize these are relatively bulky and expensive items - a standalone player costing ~$800 vs. and $700 amp/DAC unit.  Also, I have seen numerous posts declaring that the HM-801's best performance is when well recorded, reference FLAC music files (from SD card or internal memory) are sent via line out to an external amp, and that it's USB performance is disappointing.  On the other had, the iQube obviously needs a source, has no line out and appears to only accept USB input.  Despite the above logistical differences, it would be great to hear from those who have directly compared these units using what member Edwood would says as, "...REAL headphones [IEMs or headphones] with REAL music..."  Some specific comparisons that would be interesting for someone to detail are:
 
1) 16/44.1 music files:
a. on SD card or internal memory on the HM-801/iQube V2  vs.  same music via USB to the iQube V2
b. via coax line in to the HM-801/iQube V2  vs.  same music via USB to the iQube V2
c. via USB in to the HM-801/iQube V2  vs.  same music via USB to the iQube V2 
[Note: The results for c. may not be  a surprise based on reports from members stating that they did not like the HiFiMAN's USB performance.  Nonetheless, it would be good to know how bad/good it is compares to the iQube.]   
 
2) Same as above but using 24/96 files, ideally of the same music used in 1) above  <--- [Edit: It was later determine that these comparisons are not possible. See follow-up posts for details.]
 
Although I realize that this topic crosses over a few forums, including Portable Headphone Amps and possible Computer Audio, I felt this was the most appropriate area to ask these questions.  Please me know otherwise.  Looking forward to your replies.  Feel free to comment on other ways you've compared the DACs on these items using high res material. 

 

[ctm]

Has anyone compared the DAC of these highly regarded portable gear?  Or, has anyone done the DAC comparison in a more casual, less formal way?  Please comment even if the HM-801's DAC was compared to that of different portable dac/amp units.  Thanks.

 

[ctm]

From continued searches, I found the related and helpful threads listed below. 
 
http://www.head-fi.org/forum/thread/492634/hifiman-hm-801-dac-performance   <--- Hifiman 801: How does it compare to traditional usb amp/dac combo's?  
http://www.head-fi.org/forum/thread/492634/hifiman-hm-801-dac-performance <--- Hifiman HM-801 DAC performance
http://www.head-fi.org/forum/thread/506003/hifiman-801-usb-dac-vs-portable-usb-dacs   <--- Hifiman 801 USB DAC vs Portable USB DACs  
 
Unfortunately, I have not yet come across anyone who has done direct comparison of DACs in the HM-801 and iQube V2.  I see at least 3 members own the iQube V2, while at least 18 are enjoying their HiFiMAN [see what I mean about the great features of this forum?]. 
 
Has anyone done this comparison? 
If not will anyone allow me to borrow/rent their iQube V2 to see how these DACs stack up to one another?
 
A while back I sold my portable dac/amp and was planning on eventually replacing it.  I since, got a Stepdance, which has no DAC.  So I am trying to narrow down my list of other portable dac/amps to consider, including iQube V2.  Thanks.

 

[ctm]

After more research it appears that a direct comparison of these players' DACs may not be possible when 24/96 files are used.  The answer to the question below, relative to the originally proposed methods of comparison, will be most helpful.  It would be great if someone can reply with the necessary information.
 
Using 24/96 files:
a. on SD card or internal memory on the HM-801/iQube V2  vs.  same music via USB to the iQube V2
Question:  Does the iQube V2 support inputs higher than 16/44.1 via USB?  If so, which ones (16/48, 24/96, or)?   <--- No (see post below)

 
b. via coax line in to the HM-801/iQube V2  vs.  same music via USB to the iQube V2
Note:  Even if 24/96 is supported by the iQube V2, the HM-801 does not support higher than 16/48 via coax. 
 
c. via USB in to the HM-801/iQube V2  vs.  same music via USB to the iQube V2
Note:  HM-801 does not support higher than 16/48 via USB
 
If it turns out that the iQube V2 cannot handle inputs 16/48 or higher, then the comparisons of the DAC in the HM-801 to one in the iQube V2 must only use 16/44.1 music files.  Has anyone done this comparison? 

 

[ctm]

An iQube V2 owner just confirmed offline that it only does 16/44.1 and only via USB.  So redbook/CD quality files is the highest resolution possible when doing DAC comparisons between these units. 
 
So has anyone done these comparisons?

 

[Trogdor]

Quote:

After more research it appears that a direct comparison of these players' DACs may not be possible when 24/96 files are used.  The answer to the question below, relative to the originally proposed methods of comparison, will be most helpful.  It would be great if someone can reply with the necessary information.
 
Using 24/96 files:
a. on SD card or internal memory on the HM-801/iQube V2  vs.  same music via USB to the iQube V2
Question:  Does the iQube V2 support inputs higher than 16/44.1 via USB?  If so, which ones (16/48, 24/96, or)?   <--- No (see post below)

 
b. via coax line in to the HM-801/iQube V2  vs.  same music via USB to the iQube V2
Note:  Even if 24/96 is supported by the iQube V2, the HM-801 does not support higher than 16/48 via coax. 
 
c. via USB in to the HM-801/iQube V2  vs.  same music via USB to the iQube V2
Note:  HM-801 does not support higher than 16/48 via USB
 
If it turns out that the iQube V2 cannot handle inputs 16/48 or higher, then the comparisons of the DAC in the HM-801 to one in the iQube V2 must only use 16/44.1 music files.  Has anyone done this comparison? 

Coaxial supports 96Khz in.   Please check the HM-801 manual.  I have mine clocked at 96kHZ right now.

 

[ctm]

Dear Trogdor - Interesting.  I understood that although files higher than 16/48 are accepted, they are downsampled to 16/48.  Is this correct? 
 
As to the HM-801 // iQube V2 DAC, the question raised was if the iQube was capable of receiving files > 16/44.1, and it does not.  Are you suggesting to compare the DACs using 24/96 files on the HM-801 and 16/44.1 on the iQube?  Although it would be interesting to do this, it is not ideal since the upfront advantage goes to the HM-801 right? 

 

[Trogdor]

Quote:

Dear Trogdor - Interesting.  I understood that although files higher than 16/48 are accepted, they are downsampled to 16/48.  Is this correct? 
 
As to the HM-801 // iQube V2 DAC, the question raised was if the iQube was capable of receiving files > 16/44.1, and it does not.  Are you suggesting to compare the DACs using 24/96 files on the HM-801 and 16/44.1 on the iQube?  Although it would be interesting to do this, it is not ideal since the upfront advantage goes to the HM-801 right? 

No, all I'm saying is that the coax in samples at 96kHz in.