Chord Mojo DAC-amp ☆★►FAQ in 3rd post!◄★☆
Jan 7, 2016 at 12:44 AM Post #8,732 of 42,391

Mimouille

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Got jh Angie on the way, can't wait to compare to se846, with the Mojo of course, I'm hoping for a fun sound.

Just a little worried on what tips to use, I like the shure black olive tips, but idk if they will fit. I doubt it, I hear from relic it won't

Well since it took you about 3mn of research to pick a new iem, don't be surprised if you are disapointed.
 
Jan 7, 2016 at 1:22 AM Post #8,733 of 42,391

NaiveSound

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Well since it took you about 3mn of research to pick a new iem, don't be surprised if you are disapointed.


I've researched for a few days....
Why say that?

Got a good return policy with no fees, so if I don't like it, off to the next one, but I hear good things about it paired with the mojo.

Just worried about silicon tips as they aren't my fav
 
Jan 7, 2016 at 2:01 AM Post #8,735 of 42,391

stevemiddie

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I've researched for a few days....
Why say that?

Got a good return policy with no fees, so if I don't like it, off to the next one, but I hear good things about it paired with the mojo.

Just worried about silicon tips as they aren't my fav

 
Well, since you have previously stated that your new SE846'S cost $500.00 only........care to mention who this company is? 
 
Jan 7, 2016 at 5:12 AM Post #8,737 of 42,391

Watcherq

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Wow, to convert DSD, it needs minimum 2ghz Quadcore CPU
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. It is fun, but it actually doesn't improve sound quality as it said. If you want to know why, Rob already mentioned it in this post here. You can try it if you like
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http://www.head-fi.org/t/784602/chord-mojo-the-official-thread-please-read-the-3rd-post/8655#post_12226242

Yep even on a desktop PC, PCM->DSD conversion via JRMC is not better, in fact I can confirmed that the music seems softer and more distant and flat.  I used to do the PCM->4xDSD for my iFi iDSD nano.  Sounds better there on ithe iDSD nano but not with the Mojo.  I have left the settings on JRMC to remain without upsampling.
 
Jan 7, 2016 at 5:22 AM Post #8,738 of 42,391

Watcherq

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You know, if I become really filthy, filthy rich, what would I do ?  I would commission Chord to build me a desktop version of Mojo using twin Xilinx Virtex UltraScale+ (VU13P chips) which has so many times more computation power to the Artix that is powering the Mojo.  I wonder how it would sound like...
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Jan 7, 2016 at 5:25 AM Post #8,739 of 42,391

x RELIC x

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You know, if I become really filthy, filthy rich, what would I do ?  I would commission Chord to build me a desktop version of Mojo using twin Xilinx Virtex UltraScale+ (VU13P chips) which has so many times more computation power to the Artix that is powering the Mojo.  I wonder how it would sound like...:blink:  


http://www.head-fi.org/t/766517/chord-electronics-dave
 
Jan 7, 2016 at 5:28 AM Post #8,740 of 42,391

bytor33

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Converting the original file into DSD or up-sampling is a very bad idea. The rule of thumb is to always maintain the original data as Mojo's processing power is way more complex and capable than any PC or mobile device.

DSD as a format has major problems with it; in particular it has two major and serious flaws:

1. Timing. The noise shapers used with DSD have severe timing errors. You can see this easily using Verilog simulations. If you use a step change transient (op is zero, then goes high) with a large signal, then do the same with a small signal, then you get major differences in the analogue output - the large signal has no delay, the small signal has a much larger delay. This is simply due to the noise shaper requiring time for the internal integrators to respond to the error. This amplitude related timing error is of the order of micro seconds and is very audible. Whenever there is a timing inaccuracy, the brain has problems making sense of the sound, and perceives the timing error has a softness to the transient; in short timing errors screw up the ability to hear the starting and stopping of notes.

2. Small signal accuracy. Noise shapers have problems with very small signals in that the 64 times 1 bit output (DSD 64) does not have enough innate resolution to accurately resolve small signals. What happens when small signals are not properly reproduced? You get a big degradation in the ability to perceive depth information, and this makes the sound flat with no layering of instruments in space. Now there is no limit to how accurate the noise shaper needs to be; with the noise shaper that is with Mojo I have 1000 times more small signal resolution than conventional DAC's - and against DSD 64 its 10,000 times more resolving power. This is why some many users have reported that Mojo has so much better space and sounds more 3D with better layering - and its mostly down to the resolving power of the pulse array noise shaper. This problem of depth perception is unlimited in the sense that to perfectly reproduce depth you need no limit to the resolving power of the noise shaper. 

So if you take a PCM signal and convert it to DSD you hear two problems - a softness to the sound, as you can no longer perceive the starting and stopping of notes; and a very flat sound-stage with no layering as the small signals are not reproduced accurately enough, so the brain can't use the very small signals that are used to give depth perception.

The second issue in using the transport to up-sample (44.1 to 176.4 say) is that the up-samplers in a PC or mobile device are very crude, with very limited processing power and poor algorithms. This results in timing problems, and like with DSD you can't hear the starting and stopping of notes correctly. These timing problems also screw up the perception of timbre (how bright or dark instruments sound), the pitch reproduction of bass (starting transients of bass lets you follow the bass tune), and of course stereo imagery (left right placement is handled by the brain using timing differences from the ears). Now Mojo has a very advanced algorithm (WTA) that is designed to maximise timing reconstruction (the missing timing information from one sample to the next) and huge processing power to more accurately calculate what the original analogue values are from one sample to the next. Its got 500 times more processing power than normal, and this allows much more accurate reconstruction of the original analogue signal.

So the long and the short is don't let the source mess with the signal (except perhaps with a good EQ program) and let Mojo deal with the original data, as Mojo is way more capable.

Rob
 
I concur, I Can hear all the things you've discussed here when comparing a dsd vs flac of the same master & album.

 
Is that really what Rob is saying here though?  That a flac source file is better than a DSD source file of the same master or only when up-sampling PCM to DSD? 
 
Jan 7, 2016 at 5:29 AM Post #8,742 of 42,391

plinth

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One of the review members found the included short cable to be the cause of dropouts.


And I found that the supplied short cable did not have drop outs but my own longer cable did. I was concerned that the problem was my Mojo as I have not had a good experience of micro USBs soldered to boards as I have had them come loose. So I was delighted that the short cable fixed the problem. I wonder if it is to do with the tightness of the fit, with the Mojo requiring a very firm connection. It could then come down to manufacturing tolerances of the connector and perhaps the torque experience on the plug when in use as the cables do experience some tight turns when stacking.
 
Jan 7, 2016 at 5:31 AM Post #8,743 of 42,391

x RELIC x

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And I found that the supplied short cable did not have drop outs but my own longer cable did. I was concerned that the problem was my Mojo as I have not had a good experience of micro USBs soldered to boards as I have had them come loose. So I was delighted that the short cable fixed the problem. I wonder if it is to do with the tightness of the fit, with the Mojo requiring a very firm connection. It could then come down to manufacturing tolerances of the connector and perhaps the torque experience on the plug when in use as the cables do experience some tight turns when stacking.


Yes, that's more or less what I was getting at. Different cables aren't always exactly the same.
 
Jan 7, 2016 at 5:35 AM Post #8,744 of 42,391

x RELIC x

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I'm afraid not.  It is still using a gen-6 Spartan.  Very well tuned and optimized no doubt.


Haha, have you read any info on the Dave. It's orders of magnitude more resolving than the Hugo, and I would presume the Mojo as well. :wink_face:

Given that it doesn't need to fit in a small enclosure I'm sure the Spartan 6 is up to the task.
 
Jan 7, 2016 at 5:38 AM Post #8,745 of 42,391

Watcherq

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Haha, have you read any info on the Dave. It's orders of magnitude more resolving than the Hugo, and I would presume the Mojo as well.
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Given that it doesn't need to fit in a small enclosure I'm sure the Spartan 6 is up to the task.

No doubt it is much more resolving than the Hugo, but but, if you combine twin Virtex Ultrascale+ with the dedication to perfection like the Dave, I wonder what it would like... :p
 

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