Chord Mojo(1) DAC-amp ☆★►FAQ in 3rd post!◄★☆
Apr 15, 2016 at 8:02 AM Post #16,021 of 42,759
 
​Actually it's ATT and one other company will not let you root some android devices, maybe others.  I tried to root my note 4 through ATT, went to the root page, and right there in black and white it says ATT and one other company won't let you root.  Definitely switching in a few months when the contract runs out.!

 
You don't need to root to install UAPP, it's in the google play store.
 
Apr 15, 2016 at 8:32 AM Post #16,022 of 42,759
I personally think correct sounding live recordings are those that can differentiate between audiance and performers. When i listen to mojo, all become same. Every sound has same impact be it clapping or coughing from audiance. As much as guitar solo playing in front. So that in my books a caveat.


Hey there just read an article on DAR
which says
'If you sat on stage, with the musicians, your perception would be quite different from the regular audience in the actual seats. Extreme nearfield details mean things like the clacking of a woodwind’s keys, the spittle noises of brasses, the finger slides or bow scratches on strings, the breath work of singers, the squeak of a chair, the rustling of a score turned over etc.'

So I think this needs to be considered, especially with the revealing nature of Mojo. The article is about resolution and the perception of it.

http://www.digitalaudioreview.net/2016/04/kih-33-hearing-the-forest-for-the-trees/

Cheers
 
Apr 15, 2016 at 8:44 AM Post #16,023 of 42,759
Quick question, when people say android upsamples, why isit a bad thing compared to non upsampling? Playing my music through poweramp or uapp my music sounds the same to me through my setup of otg usb hifimediy android dac. I think when people talk about changes in the music of soundstage etc unless its detectable as in the equivalent of spotting two totally different colours such as black and white, the audible differences are very slight. Slight to the point where the average layman who listens to music through headphones wouldnt really pick up on?
 
Apr 15, 2016 at 8:46 AM Post #16,024 of 42,759
As the MOJO can go into line out mode and has 2 3.5" outs can one line go to an amp and one line to an active sub-woofer ?
 
Apr 15, 2016 at 8:56 AM Post #16,025 of 42,759
Quick question, when people say android upsamples, why isit a bad thing compared to non upsampling? Playing my music through poweramp or uapp my music sounds the same to me through my setup of otg usb hifimediy android dac. I think when people talk about changes in the music of soundstage etc unless its detectable as in the equivalent of spotting two totally different colours such as black and white, the audible differences are very slight. Slight to the point where the average layman who listens to music through headphones wouldnt really pick up on?

 
 
See the section 'Informative posts by Rob Watts', in post #3
 
Apr 15, 2016 at 8:59 AM Post #16,026 of 42,759
Right...hopefully somebody can help me.....I'm using the chord mojo connected to my Lg G4 via micro usb, I am using Uapp to play the music from my micro sd which is working fine but every time I try to play from my Spotify account it's not coming out of my headphones but through the phones speakers. I've had Spotify playing via the mojo before so I know the setup is capable but I'm probably missing something simple.....hope someone can help
 
Apr 15, 2016 at 9:16 AM Post #16,028 of 42,759
 
See the section 'Informative posts by Rob Watts', in post #3

I will re read post #3 cheers. I've gone through it a few times for specific things its just so vast

 
 
 
I've tried to organise it into sub-sections, and sub-sub-sections, to make it easier to find relevant information, but I suppose the topic bears reposting in the thread, so, from the suggested section, in post #3:
 
 
  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

 
Also relevant:
 
Quote:
  It is always better to give Mojo bit perfect files and let Mojo do the work, as the processing within Mojo is much more complex and sophisticated than a mobile or PC.
 
So when you have an app that has a volume control, and no bit perfect setting, then set it to full volume on the app on the assumption that this will keep the data closer to the original file.
 
The volume control function on Mojo is much more sophisticated than the PC as I employ noise shaping and I do the function at a very high internal sample rate. Hopefully using the volume set to max on the app will mean the volume coefficient is 1.0000000... so it will return the original data.
 
Rob 

 
  You can always do a listening test. If set to max against 50% say, and it hardens up (becomes brighter) with loud recordings then its clipping. If on the other hand the perception of sound-stage depth is reduced, then the volume control is degrading the sound.
 
If you do that test and can hear no difference then don't worry, its a good app volume control.
 
Rob
 
PS for fun I just did a very quick test using Dave. I listen to radio 3 using the BBC iPlayer. I normally have it set to max. I reduced the iPlayer volume control to half, boosted Dave volume control by +6dB - and yes I felt sound-stage depth was worse with lower iPlayer volume. 

 
 
Apr 15, 2016 at 9:59 AM Post #16,030 of 42,759
Any idea if Chord going to launch a DAP module for the Mojo with a display?
I think it would be great rather than to stack another DAP to it with rubber bands but rather a module that attached itself to the Mojo.
 
Apr 15, 2016 at 10:38 AM Post #16,031 of 42,759
The Questyle QP1R uses optical, not coaxial so you need a 3.5mm mini optical to TOSlink optical cable to connect to the Mojo.

The DP-X1 does not have a coaxial output and the Mojo does not take an analogue input from a line-out jack. You need to use a USB OTG cable to connect to the Mojo from the DP-X1.

Thank you for taking the time to respond. Ill act accordingly.
 
Apr 15, 2016 at 10:44 AM Post #16,032 of 42,759
Any idea if Chord going to launch a DAP module for the Mojo with a display?
I think it would be great rather than to stack another DAP to it with rubber bands but rather a module that attached itself to the Mojo.

 
 
  1. I don't know if they will ever do anything with a display, but it seems rather doubtful, considering Mojo has been touted as a smartphone companion, all along, and smartphone screens are as good as they get.
 
  1. I asked about Chord making a DAP, or transport, a couple of years ago, long before Mojo, and was told firmly that this is not something they have any desire to venture into.
 
 
If that still remains the case, then put the above 2 factors together, and I don't consider it likely that they'll make a module that would include a screen so as to totally eliminate the need for a smartphone or DAP.
 
Remember, it's not just about 'adding a screen' it would mean having to develop a GUI (do not underestimate how complex and expensive-to-develop something as seemingly-simple as a GUI can be), along with all the associated hidden control-code to interface with the hardware.
 
 
I'd love to be wrong about that, and who knows how far the SD module will take them, partially, down that road, but I just don't see a Chord 'transport-with-screen' (at least not for the next couple of years or more).
 
Heck, we all know it'd sell by the truckload, though!
beerchug.gif
 
 
Apr 15, 2016 at 11:58 AM Post #16,033 of 42,759
Hi,

I am new to this forum. I am considering purchase of Mojo, as reviews are so good. I intend to use it with my iphone and a pair of V-Moda XS.

I just wonder if having such small headphones it makes sense to buy Mojo. Will I be able to benefit from improvement in a sound quality?

Thank you,
Kamil
 
Apr 15, 2016 at 12:06 PM Post #16,034 of 42,759
So just sharing; I have the Cavalli Liquid Carbon in right now and the Mojo pairs quite well to it mainly because the Liquid Carbon has an almost magical way of taking in a single-ended signal and turning it into balanced. As my transportable/bedside rig, this sounds really awesome. 
 
Apr 15, 2016 at 12:07 PM Post #16,035 of 42,759
Hi,

I am new to this forum. I am considering purchase of Mojo, as reviews are so good. I intend to use it with my iphone and a pair of V-Moda XS.

I just wonder if having such small headphones it makes sense to buy Mojo. Will I be able to benefit from improvement in a sound quality?

Thank you,
Kamil
Hey, I had the mojo and crossfade wireless. My set up before I bought the mojo was a galaxy s6edge plus with a cayin c5 portable amp and hifimediy sabre android dac. My files were mp3.

If you arent using a decent portable amp and dac you would notice a big difference. If you are then you may be like me and not be able to tell the difference in sound.

I took the mojo back and decided I needed to upgrade my IEM's/headphones to high quality and upgrade my music files to FLAC minimum and I will try the mojo again.

For the money you could pick up a really nice pair of headphones/IEM's which would give you a bigger boost than the mojo in my experience. YMMV

Best of luck though!
 

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