HiFiMAN HM-901 visit pg 18. IMGS pg 19. NEW beta FW 1st page. . to the 901s. .new 901s FW .
Aug 3, 2013 at 12:19 PM Post #811 of 3,445
That's good to know. I see that one of the cards is 95 MB/s (the Sandisk 16GB Extreme Pro) and another one is 20MB/s. This should tell us that jitter isn't a problem with normal speed cards with HM-901. Well, unless you weren't listening close enough, ha-ha!
There is a huge difference between card speeds so I balance it out by listening to slow music with fast cards and vice versa. Problem solved.
 
Aug 3, 2013 at 12:21 PM Post #812 of 3,445
Was that a joke? If not, then please explain.
 
Aug 3, 2013 at 1:43 PM Post #816 of 3,445
My smartphones batteries has also lost all power suddenly now and then. It's annoying, yes, but not necessarily a bug that is related to HiFiMan.
 
Aug 3, 2013 at 2:25 PM Post #817 of 3,445
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What about this sandisk extreme pro sd card? It has 95 mb/s read times!

http://www.amazon.com/gp/product/B005VDRD4C/ref=ox_sc_act_title_2?ie=UTF8&psc=1&smid=A13BNE3P7C8THK

 

 
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That's a nice card for cameras, but a simple, Class 10 card has more than enough throughput for hi-rez music playback on a DAP.

Buy more GB with that money. :)

 
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Theoretically I agree, but then there are reports from different sources saying there may be sonic improvements with higher speed cards, because they will provide less jitter.

This is not only enthusiastic head-fi'ers who says this, but also the engineer who made the Tera Player.

If the HM-901 will have less jitter with very fast cards than "normal" speed cards is yet not tested AFAIK.

 
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Blind tested with all these on 901 and cannot say I notice any difference....


 
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That's good to know. I see that one of the cards is 95 MB/s (the Sandisk 16GB Extreme Pro) and another one is 20MB/s. This should tell us that jitter isn't a problem with normal speed cards with HM-901. Well, unless you weren't listening close enough, ha-ha!

Let's also look at just how "fast" of a card we need. The highest bitrate we can possibly throw at the HM-901 is a 24/192 WAV file, which has a bitrate of 9216/kbps.That equates to 1.12500 mb/s folks! The slowest card, 20mb/s, can output a maximum of 163,840 kbps.
 
Aug 3, 2013 at 2:36 PM Post #818 of 3,445
Blind tested with all these on 901 and cannot say I notice any difference....


Did you tried A-B test, same file, slowest card vs. fastest?
If there's no diference it means that there is a buffer or a resampling working on.
In the digital audio one of the most critical aspects is the synchronicity. You had a data that needs to be delivered in exactly some point in time with the lowest delay possible at the moment required. The jitter is the "noise" produced by a-synchronicity. A faster card will help to archive that if you get the data straight forward from the card and convert it to an analogical signal without any other processing in between (the case of the Tera Player that is minimalistic).
It's not about how fast you can start playing a file.
 
Aug 3, 2013 at 3:53 PM Post #819 of 3,445
This is allegedly why the HDP-R10 / DX100 apparently benefits from faster cards: it might not have a buffer. If Kkcc's findings are true, it suggests the HM-901 maybe has a buffer.
 
Aug 3, 2013 at 6:38 PM Post #823 of 3,445
I think that I would be re-playing what I listened the day before just cos I would be familiar with the material. But taking the question like the "ideal" best tracks to test the player I would say:

1. "Chan Chan" from the album Buena Vista Social Club specially to check the detail from the Compay Segundo voice in the background.
2. "Sorrow" - Pink Floyd in the version of the live album PULSE, to check the guitar intro, which has a extreme wide sound, and for the overall sound of the album.
3. "Giorgio by Moroder" - Daft Punk from their new album Random Access Memories, cos I love the track specially the second part when it becomes really intense and I'd really love to see how well the player can handle it.


The daft punk album is cool and of course, Pink Floyd Pulse is a master piece i Love the track "Keep Talking" with it's heil talk box guitar solo and powerful female response vocals!

Anyone have any recomendations for me of the very best of the best audiophile songs to try out on the HM-901. Which should be here I really hope early this week.
Can't wait to have a lamborghini in the portable audio garage.
 
Aug 3, 2013 at 7:38 PM Post #824 of 3,445
Bobby McFerrin - The Best of ... - Blue Note Years: "Friends"
That's a super demo / test track.
 
Aug 3, 2013 at 7:43 PM Post #825 of 3,445
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It will have a buffer. It's whether it's either large or good enough for the timing issues described.

Okay. If there is a SQ difference between SD cards, it must be jitter related AFAIK, and then the buffer will either clean it up or struggle doing it. Right ?
 

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