Chord Mojo(1) DAC-amp ☆★►FAQ in 3rd post!◄★☆
Apr 1, 2018 at 10:03 AM Post #35,761 of 42,759
Thanks for your reply!

Just to make it clear: Are you saying that there is no difference between the cable that goes from smartphone to mojo as compared to the cable that goes from mojo to headpones, in terms of how much the cables effect SQ?

Also, are you saying that transmitting the digital signal from my phone to the mojo via Wifi results in better SQ compared to using a cable and that that is the reason why the poly sounds better? And shouldn't the SQ improvement here be limited to the level of a an optical cable connection between data source (smartphone or poly) and mojo because the data still has to go through an optical cable to reach the mojo?

I’m saying there are differences in sound of analog signal cables, I.e. from Mojo to headphones and people have many preferences here. But, for digital cables, I believe that differences in sound result from additional, unwanted noise, and you should strive for a USB cable that sounds the same as optical, which would indicate no added interference or noise.

And yes, Wi-Fi May result in better SQ, as @NoTimeFor stated above also.
 
Apr 2, 2018 at 4:52 AM Post #35,762 of 42,759
Hi Mojo lovers,

I use my Mojo for more than a year and I am very happy with it. My source is an Iphone 6s with Tidal and I use the USB input of the Mojo. Once I tried Mojo driven by my Heed Audio CD transport thru optical cable and the SQ was significantly better. I am wondering if the difference is due to the better digital source or due to optical instead of USB input of Mojo. Because of this I started thinking about to try an USB SPDIF converter.
So my question to you guys:
Do anyone use an USB SPDIF converter with Mojo? If yes does it improves the SQ?
Thanks!
 
Apr 2, 2018 at 5:55 AM Post #35,763 of 42,759
So my question to you guys:
Do anyone use an USB SPDIF converter with Mojo? If yes does it improves the SQ?
Thanks!

I have seen praise for the Schiit Eitr for this. But, of course, that is not a portable solution.
 
Apr 2, 2018 at 6:18 AM Post #35,764 of 42,759
Hi Mojo lovers,

I use my Mojo for more than a year and I am very happy with it. My source is an Iphone 6s with Tidal and I use the USB input of the Mojo. Once I tried Mojo driven by my Heed Audio CD transport thru optical cable and the SQ was significantly better. I am wondering if the difference is due to the better digital source or due to optical instead of USB input of Mojo. Because of this I started thinking about to try an USB SPDIF converter.
So my question to you guys:
Do anyone use an USB SPDIF converter with Mojo? If yes does it improves the SQ?
Thanks!
I am somewhat of a noob but shouldn't the cable switch be the reason? The only role the source is playing is to provide the data. The Dac is doing all the audible footwork (converting the digital into a analogue signal). The only reason why a source could sound bad is if it has lots of noise and a smart-phone (in airplane mode) should be pretty ideal for that since it's battery powered.
 
Apr 2, 2018 at 7:12 AM Post #35,765 of 42,759
Hi Mojo lovers,

I use my Mojo for more than a year and I am very happy with it. My source is an Iphone 6s with Tidal and I use the USB input of the Mojo. Once I tried Mojo driven by my Heed Audio CD transport thru optical cable and the SQ was significantly better. I am wondering if the difference is due to the better digital source or due to optical instead of USB input of Mojo. Because of this I started thinking about to try an USB SPDIF converter.
So my question to you guys:
Do anyone use an USB SPDIF converter with Mojo? If yes does it improves the SQ?
Thanks!
Rob Watts posts that for the Mojo, the optical input is slightly better than the usb input. The principle reasons are that optical is immune to the effects of RFI, and is also isolated from any electrical noise being generated within the source device.
The phone will generate some electrical noise, plus the usb cable will act like an aerial for RFI - and this noise/RFI will cause the music to sound brighter, compared to if you use the optical input. You can remove much of the RFI by adding a ferrite choke to the usb cable, but the electrical noise will remain.
I use optical for my Mojo and hugo 2, and only rarely use usb.
 
Apr 2, 2018 at 8:46 AM Post #35,766 of 42,759
which optical cables mike?
 
Apr 2, 2018 at 12:07 PM Post #35,768 of 42,759
Apr 2, 2018 at 12:54 PM Post #35,769 of 42,759
Hi Mojo lovers,

I use my Mojo for more than a year and I am very happy with it. My source is an Iphone 6s with Tidal and I use the USB input of the Mojo. Once I tried Mojo driven by my Heed Audio CD transport thru optical cable and the SQ was significantly better. I am wondering if the difference is due to the better digital source or due to optical instead of USB input of Mojo. Because of this I started thinking about to try an USB SPDIF converter.
So my question to you guys:
Do anyone use an USB SPDIF converter with Mojo? If yes does it improves the SQ?
Thanks!

I have seen praise for the Schiit Eitr for this. But, of course, that is not a portable solution.

My understanding is that is that a USB SPDIF converter takes the signal from a source (e.g. a smartphone) and then allows for it to be further transported via Toslink or Coaxial to the DAC (the Mojo for example).

The advantage would be that any noise from the smartphone, the USB that connects smartphone and USB-SPDIF-converter and the USB-SPDIF-converter itself would not arrive at the DAC (Mojo) because an optical cable (Toslink) has being doing the transport to the DAC (optical cables don't take up noise).

Did I get anything wrong here?

And purely from a sound quality perspective, does such an USB SPDIF converter achive the same result as the Chord Poly and might even be better because the Poly might be noisy itself (see
https://www.head-fi.org/goto/post?id=13161612#post-13161612)
AND is near the Mojo by design?
 
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Apr 2, 2018 at 1:35 PM Post #35,771 of 42,759
My understanding is that is that a USB SPDIF converter takes the signal from a source (e.g. a smartphone) and then allows for it to be further transported via Toslink or Coaxial to the DAC (the Mojo for example).

The advantage would be that any noise from the smartphone, the USB that connects smartphone and USB-SPDIF-converter and the USB-SPDIF-converter itself would not arrive at the DAC (Mojo) because an optical cable (Toslink) has being doing the transport to the DAC (optical cables don't take up noise).

Did I get anything wrong here?

And purely from a sound quality perspective, does such an USB SPDIF converter achive the same result as the Chord Poly and might even be better because the Poly might be noisy itself (see
https://www.head-fi.org/goto/post?id=13161612#post-13161612)
AND is near the Mojo by design?
You are right about optical connection, and i use optical almost exclusively. I have posted before that optical results in music output that sounds like a very clean reproduction of music. Playing the same track, usb sounded slightly brighter, as if one was at the actual performance - the brightness is caused by low levels of electrical noise fooling the brain, but some people do prefer this brightness.
The post that you quote was by Grumpy, and he was well known to have a sceptical viewpoint about everything that Chord posted. @Mojo ideas responded by mentioning many times that Chord had used a team of RFI experts to design the PCB, which was itself 10 layer, to further reduce the RFI contamination within the PCB. During the past month, now that owners have both the Poly, and the firmware updates, we are seeing posts stating that now Mojo + poly, produces better sound quality than Mojo on its own. Based on those posts, I think it is safe to conclude that Poly is not noisy, and that @Mojo ideas was correct all along.
So don't have any fears about Poly being noisy.
 
Apr 2, 2018 at 3:23 PM Post #35,772 of 42,759
You are right about optical connection, and i use optical almost exclusively. I have posted before that optical results in music output that sounds like a very clean reproduction of music. Playing the same track, usb sounded slightly brighter, as if one was at the actual performance - the brightness is caused by low levels of electrical noise fooling the brain, but some people do prefer this brightness.
The post that you quote was by Grumpy, and he was well known to have a sceptical viewpoint about everything that Chord posted. @Mojo ideas responded by mentioning many times that Chord had used a team of RFI experts to design the PCB, which was itself 10 layer, to further reduce the RFI contamination within the PCB. During the past month, now that owners have both the Poly, and the firmware updates, we are seeing posts stating that now Mojo + poly, produces better sound quality than Mojo on its own. Based on those posts, I think it is safe to conclude that Poly is not noisy, and that @Mojo ideas was correct all along.
So don't have any fears about Poly being noisy.

That would answer the question whether the poly + mojo produces better SQ results than the mojo + usb cable.

What about the other question: Shouldn't a USB-SPDIF-converter produce the same effect as the Poly since both options (USB-SPDIF-converter and Poly) eliminate the USB cable and replace it with a optical cable (I have read somewhere that the Poly transports the digital signal via an optical cable to the Mojo). I am asking because there are pretty inexpensive and compact USB-SPDIF-converters which could produce the same results as the Poly for far less money. This conclusion is based on the assumption I described in the post you replied to which is that the only thing that matters is that the digital signal is fed to the mojo by an optical cable. This conclusion would also imply that there is no other quality a USB-SPDIF-converter would have to have and that any (cheap) USB-SPDIF-converter would do.

I appreciate anyone who can find a fault in my argument.

@miketlse do you have the link to the post which refuted the critique I cited?
 
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Apr 2, 2018 at 3:32 PM Post #35,773 of 42,759
That would answer the question whether the poly + mojo produces better SQ results than the mojo + usb cable.

What about the other question: Shouldn't a USB-SPDIF-converter produce the same effect as the Poly since both options (USB-SPDIF-converter and Poly) eliminate the USB cable and replace it with a optical cable (I have read somewhere that the Poly transports the digital signal via an optical cable to the Mojo). I am asking because there are pretty inexpensive and compact USB-SPDIF-converters which could produce the same results as the Poly for far less money. This conclusion is based on the assumption I described in the post you replied to which is that the only thing that matters is that the digital signal is fed to the mojo by an optical cable. This conclusion would also imply that there is no other quality a USB-SPDIF-converter would have to have and that any (cheap) USB-SPDIF-converter would do.

I appreciate anyone who can find a fault in my argument.

@miketlse do you have the link to the post which refuted the critique I cited?

FWIW, I used to drive my Mojo via USB and never liked the combo with the Utopia, harsh/digital sounding. Decided to experiment and buy a Schiit Eitr (USB/Coax converter) to use with the Mojo. Completely removed the harshness I was hearing via USB. After that I upgraded to the Hugo 2 and notice the same issues with USB vs coax.
 
Apr 2, 2018 at 4:05 PM Post #35,774 of 42,759
FWIW, I used to drive my Mojo via USB and never liked the combo with the Utopia, harsh/digital sounding. Decided to experiment and buy a Schiit Eitr (USB/Coax converter) to use with the Mojo. Completely removed the harshness I was hearing via USB. After that I upgraded to the Hugo 2 and notice the same issues with USB vs coax.

Excuse my ignorance, how did you connect your Mojo or Hugo 2 to the Eitr? Does it require a toslink cable? If not, what? The only thing that I know at this point is that I need a usb A to usb B cable to connect the Eitr to my iPhone 6s.
 
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Apr 2, 2018 at 4:13 PM Post #35,775 of 42,759
Excuse my ignorance, how did you connect your Mojo or Hugo 2 to the Eitr? Does it require a toslink cable? If not, what? The only thing that I know at this point is that I need a usb A to usb B cable to connect the Eitr to my iPhone 6s.

Eitr uses digital coax, I use a Black Dragon 75-ohm RCA to 3.5mm mono digital coax cable.
 

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