Chord Mojo(1) DAC-amp ☆★►FAQ in 3rd post!◄★☆
Feb 10, 2016 at 8:17 AM Post #11,026 of 42,765
   
That means when using Mojo as a desktop dac it benefits from a usb filter such as uptone regen/jitterbug/wyrd or a usb to optical converter like the m2tech hiface?

the USB filters, would seem the most beneficial. It sounds like the best input is Optical if you are wanting best ground isolation/sound. I was using my Mojo with a simple cable before but now gonna use the Jitterbug I have to see if I hear a difference. 
 
Feb 10, 2016 at 8:19 AM Post #11,027 of 42,765
Two questions related to Rob Watts' comments on optical output as a source to the Mojo;

1. What is audio "glare"? What does it sound like? And how does one distinguish it from detail?

2. Is the conclusion that one with an Apple computer should be using its optical/toslink output (that also serves as a headphone output) rather than its USB output, even if one uses an AudioQuest Jitterbug, Schiit Wyrd, Uptone Regen and an Akiko USB tuning stick, or similar devices ?
 
Feb 10, 2016 at 8:47 AM Post #11,028 of 42,765
  To eliminate the RF and signal correlated noise on USB you need galvanic isolation. The downside to galvanic isolation is that it draws power from the source - which is not something we can do with a mobile product. . . .
 
 . . . . If you can do it, use the optical, as this usually sounds the best and is completely isolated. Optical has a undeservedly poor reputation, as it sounds much smoother and darker than other inputs, and this is just a feature of lower noise floor modulation - its smoother with better instrument separation and focus  . . . 
 
Rob

 
 
Two questions related to Rob Watts' comments on optical output as a source to the Mojo;

1. What is audio "glare"? What does it sound like? And how does one distinguish it from detail?

2. Is the conclusion that one with an Apple computer should be using its optical/toslink output (that also serves as a headphone output) rather than its USB output, even if one uses an AudioQuest Jitterbug, Schiit Wyrd, Uptone Regen and an Akiko USB tuning stick, or similar devices ?

 
I`m quite pleasantly blown away by Rob`s words.  I have alway thought optical sounded better somehow, but believed USB would be better somehow.  
 
It seems the answer to your second question is yes, and I will start using my Macbook`s optical out with my portables form now on . . .   
 
Feb 10, 2016 at 9:07 AM Post #11,029 of 42,765
To eliminate the RF and signal correlated noise on USB you need galvanic isolation. The downside to galvanic isolation is that it draws power from the source - which is not something we can do with a mobile product. All Chord desktop DAC's have USB galvanic isolation now.

That said, mobile sources are much lower noise - they have very efficient processors, unlike a PC, and there is no ground, so circulating currents are much less, so it is a much smaller problem with mobile. If you can do it, use the optical, as this usually sounds the best and is completely isolated. Optical has a undeservedly poor reputation, as it sounds much smoother and darker than other inputs, and this is just a feature of lower noise floor modulation - its smoother with better instrument separation and focus - but lack of glare is often confused with a lack of detail resolution. Listening tests must be done with a lot of care, as it is easy to draw the wrong conclusions!

Rob


Thanks, Rob. Given this, does that imply that the add-on modules will connect to Mojo via optical or coax, where possible (like SD reader or Bluetooth)?
 
Feb 10, 2016 at 9:13 AM Post #11,030 of 42,765
Two questions related to Rob Watts' comments on optical output as a source to the Mojo;

1. What is audio "glare"? What does it sound like? And how does one distinguish it from detail?

2. Is the conclusion that one with an Apple computer should be using its optical/toslink output (that also serves as a headphone output) rather than its USB output, even if one uses an AudioQuest Jitterbug, Schiit Wyrd, Uptone Regen and an Akiko USB tuning stick, or similar devices ?

Glare is normally used for extreme form of hardness or grain in the treble. So I guess one could say going from bad to good glare, grainy, hard, bright, smooth, dark. 
 
Distinguishing it from detail is tricky as a brighter sound is easy to confuse it with more detail resolution. Indeed, truly more transparency, does sound brighter. So you have to be very careful, and I have been caught out in the past. One way of recognising it is with timbre - it the extra brightness is noise floor modulation for example, then all instruments will sound brighter - even those that are supposed to sound rich and dark. But if the brightness is better detail resolution, then smooth instruments will just sound clearer, not brighter. Also, if instrument separation and focus is worse, then it is not more transparency.
 
When somebody says it sounds better, but can't actually describe in details what the differences are, be warned! They may be preferring distortion. Fortunately, our lizard brain ignores all this - if its really better, it will be more emotional and involving, so you should use this as your goal. But assessing whether its more emotional or musical takes a lot of time, you can't do it on a quick AB test.
 
The USB filter devices help (hopefully) but do not solve the problem. It has to use galvanic isolation to do it properly.
 
Rob
 
Feb 10, 2016 at 10:40 AM Post #11,032 of 42,765
  To eliminate the RF and signal correlated noise on USB you need galvanic isolation. The downside to galvanic isolation is that it draws power from the source - which is not something we can do with a mobile product. All Chord desktop DAC's have USB galvanic isolation now. That said, mobile sources are much lower noise - they have very efficient processors, unlike a PC, and there is no ground, so circulating currents are much less, so it is a much smaller problem with mobile

Maybe a good idea for Hugo mk2 would be to have one USB with isolation and the other without instead of the HD & SD USB inputs so desktop users can have better sound without needing extra hardware e.g wyrd or regen, and still have the best portable device.
 
Feb 10, 2016 at 11:11 AM Post #11,033 of 42,765
I just wish I could find a true optical cable thay would fit the way this cable fits

(this is what I'm currently using)


My price limit is 30$ for a true optical cables (short-like the picture above)

For me to pair my dx80 to mojo properly and to sound as good as described on this thread, please anyone... Help




This is what I have now, it sounds good, but I feel it can definitely sound better with a proper cable to connect them both
 
Feb 10, 2016 at 11:17 AM Post #11,034 of 42,765
I just wish I could find a true optical cable that would fit the way this cable fits

(this is what I'm currently using)


My price limit is 30$ for a true optical cables (short-like the picture above)

For me to pair my dx80 to mojo properly and to sound as good as described on this thread, please anyone... Help




This is what I have now, it sounds good, but I feel it can definitely sound better with a proper cable to connect them both

 
 
 
I mean no offence by this, but please... you've posted that top picture multiple times in this thread.
 
Currently, the only optical cable that looks like your current stereo analogue cable (which, if I'm not mistaken, you're using as though it was a true co-ax cable), would be the Sysconcepts cable, which has been specifically modified by Sysconcepts to be so extremely short. That cable has been discussed many, many times, in this thread, and you know that that information is linked in the 3rd post of this thread.  Ooops - + the (also expensive) MoonAudio one - thanks cj3209, for reminding me!)
 
It will not cost $30, though, because it is not a mass-produced cable.
 
That's unfortunate, but it's just the way things currently are.
 
We will probably eventually see cheaper equivalents, but not until a big optical cable vendor considers that the DAC-Amp stacking sector of the marketplace is big enough to make it worthwhile (the worldwide success of Mojo is making it more and more worthwhile, though, which means there may be some hope for you!)
 
.
 
Feb 10, 2016 at 11:19 AM Post #11,035 of 42,765
I just wish I could find a true optical cable thay would fit the way this cable fits

(this is what I'm currently using)


My price limit is 30$ for a true optical cables (short-like the picture above)

For me to pair my dx80 to mojo properly and to sound as good as described on this thread, please anyone... Help




This is what I have now, it sounds good, but I feel it can definitely sound better with a proper cable to connect them both

 
I just got this optical cable from japan (use Google chrome to auto translate)
 
http://www.amazon.co.jp/dp/B00MGHQO4G/ref=olp_product_details?_encoding=UTF8&me=
 

 
Feb 10, 2016 at 11:22 AM Post #11,036 of 42,765
Feb 10, 2016 at 11:22 AM Post #11,037 of 42,765
  I just got this optical cable from japan (use Google chrome to auto translate)
 
http://www.amazon.co.jp/dp/B00MGHQO4G/ref=olp_product_details?_encoding=UTF8&me=

 
 
Well, that's nearer to a super-short cable, but I'm not sure I'd trust it in my pocket, because it's not as low-profile as the Sysconcepts one.
 
Feb 10, 2016 at 11:24 AM Post #11,038 of 42,765
Here's another one:
http://www.moon-audio.com/silver-dragon-toslink-form-fit-digital-cable.html

Not $30 though, sorry.

CJ


Lol, um no.
confused_face.gif

 
Feb 10, 2016 at 11:26 AM Post #11,040 of 42,765
There's definitely a niche that needs filling, for a sensible-priced uber-short, uber-low-profile optical cable, but it must be tricky to get them around a very tight radius bend, without failure, and without costing too much in manual labour to produce.
 

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