Chord Mojo(1) DAC-amp ☆★►FAQ in 3rd post!◄★☆

[ExpatinJapan]

I should pick up a Mojo.
It seems to be a common question when it comes to reviews and comparisons

'how does this xxxx compare to the Mojo?'

 

[seamon]

I should pick up a Mojo.
It seems to be a common question when it comes to reviews and comparisons

'how does this xxxx compare to the Mojo?'

Pretty much the benchmark of portable audio

 

[dip registered]

So I finally got around to testing out my new 4 foot Meenova micro usb to lightning cable. Works fine. Feels well made. I like the lack of a lightning adapter. The longer cable means I can keep my phone in the front pocket of jeans and leave the Mojo in my inside jacket pocket. Also not getting interference when I place the iPhone and mojo close together - wonder if that was caused by the adapter.

I had no idea that a cable like this would work, seeing as though sellers usually push/guide you to buy an apple camera kit and a USB cable with the mojo.

This seems way better. Does it actually work/connect as it's supposed to? I'm keen to get one.

 

[WCDchee]

What LPS are you using?

Nothing too fanciful really the Jays audio LPS in which the bulk order was done during the geek pulse period probably goes for like 50usd used if you're lucky.

I'm not one to hype, regretted immediately after buying the recovery during the preorder special and was 100% ready to sell it immediately. Decided to give it a shot though and it was too big a difference to ignore. After which I had the LPS lying around and plugged it in and again a pretty damn big difference. So it's been in my setup since.

 

[zerolight]

I had no idea that a cable like this would work, seeing as though sellers usually push/guide you to buy an apple camera kit and a USB cable with the mojo.

This seems way better. Does it actually work/connect as it's supposed to? I'm keen to get one.

There's a couple of users in this thread using it too. I have a CCK and replaced it with this cable and it's perfect. There used to be a whole bunch of cables in the faq in this thread but they stopped working after update 10 gore ios. I'm told the more expensive Zee cable still works too but this Meenova in short or long is good value.

 

[GreenBow]

 

   
Yeah smoother, detail still there, more 3d, fuller (not the best at describing lol)
 
You'd think it would sound the same, I suppose the main difference is the mojo is using UAPPs driver opposed to mojos own windows driver on the laptop...

 
Rob talks a lot about noise getting in to the audio path, creating noise floor modulation, and spicing up the sound (like audio MSG - his words) and killing depth. That's the whole reason for people using USB cleaners in the path, to clean up noise in the audio path. What you report sounds like the battery powered phone is sending a cleaner signal with less noise. I'm sure it has nothing to do with the UAPP app if there is no EQ engaged and it's sending the signal bit-perfect.

 
Please everyone,
 
I have been wondering about the effect of EQ-ing on the bit-perfect signal. The signal can't really be called bit-perfect once EQ-ed, since it's not the original signal.
 
What I mean is how much or in what way is the signal affected. Sorry everyone if this is off topic.
 
I am using Mojo and JRiver. I found recently that EQ-ing in JRiver made a much better experience with Grado SR225e headphones.
 
The 225e have a bit of a bright signature. I did EQ the lower frequencies up but the result was not really satisfactory. Someone mentioned that we are really supposed to EQ down, and not up. Anyway I tried that in the bright range of the headphones. I found it works well, since there is no bright glare. I hear the mids and lower notes much richer. (I only EQ-d three bands down 3, 6, and 12KHz, by an average of 3.5dB. (It makes such a difference.))
 
However going back to EQ-ing. I am wondering how it affects the signal. Does it literally only cut a little off the frequencies EQ-ed? Or does it have some wider effect?

 

[jmills8]

Please everyone,

I have been wondering about the effect of EQ-ing on the bit-perfect signal. The signal can't really be called bit-perfect once EQ-ed, since it's not the original signal.

What I mean is how much or in what way is the signal affected. Sorry everyone if this is off topic.

I am using Mojo and JRiver. I found recently that EQ-ing in JRiver made a much better experience with Grado SR225e headphones.

The 225e have a bit of a bright signature. I did EQ the lower frequencies up but the result was not really satisfactory. Someone mentioned that we are really supposed to EQ down, and not up. Anyway I tried that in the bright range of the headphones. I found it works well, since there is no bright glare. I hear the mids and lower notes much richer. (I only EQ-d three bands down 3, 6, and 12KHz, by an average of 3.5dB. (It makes such a difference.))

However going back to EQ-ing. I am wondering how it affects the signal. Does it literally only cut a little off the frequencies EQ-ed? Or does it have some wider effect?

If Bit "perfect" is not sounding "perfect" and you use EQ and it brings a smile on your face then thats PERFECT.

 

[WayTooCrazy]

Excuse my ignorance... but I have a Windows 10 Tablet that I use for pretty much everything. It only provides me up to 96Khz sample rate, but allows me to set the system to output 32/384. I assume this will lock the system and upsample everything. I've tried Onkyo HF Player on my LG V20 to the Mojo and that does allow me to utilize the different sampling rates based on the file itself. This includes DSD (which I still haven't figured out how to get out of my Windows 10 system). The last pic shows my out for DSD using PCM conversion or DoP. I can even use DSD of different frequencies and my phone will show the difference (again... only outputting to the Mojo). Anyone have any links to point me to how to get this working on my Windows 10 machine like it does on my phone? 

 

[x RELIC x]

Spoiler

Excuse my ignorance... but I have a Windows 10 Tablet that I use for pretty much everything. It only provides me up to 96Khz sample rate, but allows me to set the system to output 32/384. I assume this will lock the system and upsample everything. I've tried Onkyo HF Player on my LG V20 to the Mojo and that does allow me to utilize the different sampling rates based on the file itself. This includes DSD (which I still haven't figured out how to get out of my Windows 10 system). The last pic shows my out for DSD using PCM conversion or DoP. I can even use DSD of different frequencies and my phone will show the difference (again... only outputting to the Mojo). Anyone have any links to point me to how to get this working on my Windows 10 machine like it does on my phone? 

You should give this a read from the Mojo designer first:

Spoiler

Originally Posted by Rob Watts View Post

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

 

[WayTooCrazy]

You should give this a read from the Mojo designer first:

That is fine and all... my entire point wasn't really about DSD. It was about the fact that even setting my OS to 24/192 or 32/384... the frequency indicator on the power button of the Mojo never changes. So, it is the frequency I set at the OS level. Which, if I play a 16/44.1 FLAC... it still shows the color for 192Khz. It doesn't do this on my phone. I was wondering if there was a way to get my Tablet to simply pass off the data to the Mojo and let it process the signal without upsampling.

 

[x RELIC x]

That is fine and all... my entire point wasn't really about DSD. It was about the fact that even setting my OS to 24/192 or 32/384... the frequency indicator on the power button of the Mojo never changes. So, it is the frequency I set at the OS level. Which, if I play a 16/44.1 FLAC... it still shows the color for 192Khz. It doesn't do this on my phone. I was wondering if there was a way to get my Tablet to simply pass off the data to the Mojo and let it process the signal without upsampling.

My apologies, I thought you wanted to upsample everything. I completely misread your post.

For DSD you need to send it over DoP for the Mojo. As far as why your tablet is upsampling everything and your phone is not I can only guess that you need to manually set the Win10 tablet sampling rate the same as your files (tedious if you have a lot of sampling rate variety) or use an audio program that automatically outputs the correct sampling rate. Hopefully those that use Win10 for music playback can help. Incidentally, have you tried installing Chord's driver for the Mojo on the Tablet?

 

[WayTooCrazy]

My apologies, I thought you wanted to upsample everything. I completely misread your post.

For DSD you need to send it over DoP for the Mojo. As far as why your tablet is upsampling everything and your phone is not I can only guess that you need to manually set the Win10 tablet sampling rate the same as your files (tedious if you have a lot of sampling rate variety) or use an audio program that automatically outputs the correct sampling rate. Hopefully those that use Win10 for music playback can help. Incidentally, have you tried installing Chord's driver for the Mojo on the Tablet?

Yes. I'm still looking through "ComputerAudiophile" as well. I just "might" install Android on my tablet in Dual Boot mode to make this easier.

 

[DoctaCosmos]

Tried looking it up but didn't find anything. My sample rate ball is always on 44 red when I put into my computer. When using jrivermediajukebox and playing 96khz music it's still red

 

[rkt31]

I have used mojo with laptop, Android ( Uapp ) and dap (fiio x3 coaxial) . fiio route sounds with least sound stage width. android (Uapp ) route has the widest soundstage but after some time you realize that it is noise which partly gives the impression of extra soundstage width. with laptop the soundstage is better than fiio x3 . now if add means of reducing rfi and emi ( ferrite and jitterbug ) all three benefit but the best and most realistic and fluid presentation is by laptop , may be it is due to asynchronous transfer and removal of rfi and emi by jitterbug and ferrite chokes.

 

[Music Alchemist]

  Please everyone,
 
I have been wondering about the effect of EQ-ing on the bit-perfect signal. The signal can't really be called bit-perfect once EQ-ed, since it's not the original signal.
 
What I mean is how much or in what way is the signal affected. Sorry everyone if this is off topic.
 
I am using Mojo and JRiver. I found recently that EQ-ing in JRiver made a much better experience with Grado SR225e headphones.
 
The 225e have a bit of a bright signature. I did EQ the lower frequencies up but the result was not really satisfactory. Someone mentioned that we are really supposed to EQ down, and not up. Anyway I tried that in the bright range of the headphones. I found it works well, since there is no bright glare. I hear the mids and lower notes much richer. (I only EQ-d three bands down 3, 6, and 12KHz, by an average of 3.5dB. (It makes such a difference.))
 
However going back to EQ-ing. I am wondering how it affects the signal. Does it literally only cut a little off the frequencies EQ-ed? Or does it have some wider effect?

 
I did find it odd that DSP can be applied in bit-perfect output modes, but what can ya do...
 
The answer is simply that it is affected by the extent of the EQ settings you use.
 
Headphones alter the signal more than anything else. Naturally, you have to alter the signal (typically in the digital realm with software EQ, but you can also use an analog hardware equalizer, though in my opinion digital is higher quality) to compensate for this, so there's nothing wrong with EQ. But you have to learn to do it the right way. There are far more ways to ruin the sound with EQ than there are to make it more accurate.
 
For the highest quality, use a parametric equalizer. You can set the exact amount to cut or boost each frequency, and you can control the bandwidth, which is basically altering anywhere from a large area of frequencies or just a tiny area with each setting.
 
Here are some EQ guides to get you started:
http://www.head-fi.org/t/796791/the-most-reliable-easiest-way-to-eq-headphones-properly-to-achieve-the-most-ideal-sound-for-non-professionals
http://www.head-fi.org/t/794467/how-to-equalize-your-headphones-2016-update
http://www.head-fi.org/t/615417/how-to-equalize-your-headphones-advanced-tutorial-in-progress
http://www.head-fi.org/t/587703/how-to-equalize-your-headphones-a-tutorial-part-2
http://www.head-fi.org/t/413900/how-to-equalize-your-headphones-a-tutorial
 
Download this frequency sweep and play it in a video player. It will let you see the peaks and dips of any headphone.
 
https://www.dropbox.com/s/pyi1gug2s2jumzq/sweep.mp4?dl=0
 
I usually start with a frequency sweep to get an idea of things, but I always equalize using tons of music, especially complex music with many frequencies going on at once.
 
Also don't forget to reduce the gain in your player by at least the amount of your largest boost/cut.
 

  I was wondering if there was a way to get my Tablet to simply pass off the data to the Mojo and let it process the signal without upsampling.

Tried looking it up but didn't find anything. My sample rate ball is always on 44 red when I put into my computer. When using jrivermediajukebox and playing 96khz music it's still red

 
To those encountering issues with the sample rate light not corresponding to your music: Use bit-perfect output in your player. (Don't bother with the Windows settings, since it should bypass them.) I use Chord's ASIO driver in foobar2000. WASAPI and KS are alternative modes you can use. If one doesn't work, try the other two. This should fix it. If it doesn't, let me know.