Chord Mojo(1) DAC-amp ☆★►FAQ in 3rd post!◄★☆
Feb 11, 2016 at 5:25 AM Post #11,116 of 42,765
 
  The problem with galvanic isolation is that the USB decoder chip and the data transmitter is powered from the mobile phone. There is no point in having 8 hours on Mojo if your mobile phone battery is depleted earlier. That said, you really need isolation when using a PC; its an order of magnitude smaller problem when using mobile phones, as everything is battery with no ground loops, and mobiles are incredibly power efficient compared to PC's - which gives you very much lower RF noise.

I can see the logic behind not including a galvanic isolation on Mojo as it is intended for mainly mobile use.. However, i'm researching a dac/amp for:
 50% desktop use as a dac only, connected to my pc and feeding both my headphone amp and speaker amp
 30% laptop use when away from home as a dac/amp
 20% connected to my mobile phone when traveling
 
Until now I found Mojo the best candidate, 2 line outs for home use, great SQ, can power HD650 and easy to carry - But in 80% of the cases i would need a galvanic isolation - will Chord provide in the future such device, or can u recommend what specs this devices should have if bought from other companies? 


I am using my Mojo as my portable and home use. I would say galvanic isolation is not a need, the power line and data line is already split like the Hugo and there is the option to use optical cable with PC and laptops.
 
I have no issues using my Mojo with USB from my PC and have ordered an optical cable to see if there is going to be any real improvements.
 
At this price point, if you spilt up the same money and get a desktop DAC and another one for portable use. I don't even know if you can get one with galvanic isolation, let alone similar quality. I guess you are just worrying too much.
 
Feb 11, 2016 at 5:53 AM Post #11,117 of 42,765
Just thought i'd share my thoughts on my newly acquired Mojo. I've not had the pleasure of auditioning the Hugo, but the Mojo is definitely my favorite sounding DAC right now, let me describe why.

I've not come across something as revealing as the Mojo (comparing to what I currently own/auditioned). I noticed that it has an uncanny ability to resolve every single detail, every sound cue, whether soft or loud, they are effortlessly audible yet completely harmonised as a whole resulting in exceptional dynamics. It's noise floor is so dark, I suspect this adds to the perceived increase in dynamics. Not that my other sources have background noise, it's somehow just much much darker on the Mojo, for the lack of a better description.

Everything on it sounds so natural, I'm not sure how to accurately describe this, but perhaps it has something to do with the timing transients? Every time I swap back to my other sources, they sound more artificial, like I know that they were coming out of a digital-to-analog converter.

Of the sources that I own, perhaps only the Hifiman HM901 is somewhat at similar performance levels to the Mojo. Now, I dislike measuring and comparing between audio equipment because fundamentally, I believe the best sound is the one that you're happy with, but in this scenario I'm throwing in the HM901 solely as a comparison. The HM901 I feel, has a slightly larger soundstage, but otherwise has less controlled bass (although more in quantity), less resolution, dynamics and treble extension. However, that still doesn't detract from the fact that the HM901 is still an excellent sounding source, not to mention it has balanced outputs. It's just rather unfortunate that my ears had to cross paths with a Mojo!

Before I close, I'd like to add some interesting effects the Mojo has had on my audiophile friends. One of them, upon hearing the Mojo through his JH Angies immediately commented on the incredible detail retrieval and sense of ambiance, instant believer. Another friend, who's more of a speaker guy, I lent him my Mojo to bypass his SACD player DAC being hooked up to a pair of B&W 800 Diamond speakers. He immediately prefers the sound out of the Mojo for being to render the tonality of the piano more accurately (he's a pianist who is able to tell apart different piano manufacturers just by listening). Btw, he is still in possession of my Mojo and i'm now back to using my HM901 lol. He is now looking into a Chord Hugo TT.

For the record, I'm mostly an IEM guy, and my favourite pairing with the Mojo by far is with the Etymotic ER4PT (converted to S). The amount of detail retrieval on this pairing is simply insane. It's been a long time since i've been this satisfied with an audio purchase, and it feels (sounds?) good :)
 
Feb 11, 2016 at 6:08 AM Post #11,118 of 42,765
 
I am using my Mojo as my portable and home use. I would say galvanic isolation is not a need, the power line and data line is already split unlike the Hugo and there is the option to use optical cable with PC and laptops.
 
I have no issues using my Mojo with USB from my PC and have ordered an optical cable to see if there is going to be any real improvements.
 
At this price point, if you spilt up the same money and get a desktop DAC and another one for portable use. I don't even know if you can get one with galvanic isolation, let alone similar quality. I guess you are just worrying too much.


Hugo does not take power through either of it's USB ports.
 
Feb 11, 2016 at 8:10 AM Post #11,119 of 42,765
Hi the difficulty we face with optical outputs from all products is that they don't work above 192k we believe our input might well work above 192 k but we can't test for it. If be happy to hear from you if you can find a source with an output greater than the present 192 kHz limit.


Hello John,
I am not sure I understand your post correctly? What I meant is  that since optical is limited to 24/192 I would prefer USB  to work  without  any  RF /EMI problems on future products.
It is not like I am having constant problems with my HUGO, but sometimes when I least expect it there are drop-outs and hardening of the otherwise very good SQ.
I actually auditioned Mojo via Sennheiser's new HD800S for  about four hours today at Jaben.
I have to confess I had no RF/EMI problems at all playing from my macbook via USB all the time and now and then switching between Mojo and my Hugo.
And I also have to say that I am completely  baffled at how good this little thing sounds on real hi res material like DXD recorded material from 2L.
Morten Lindberg's  DXD recording of Beethoven's last piano sonata Opus 111, sounded absolutely  superb but a bit different, tighter  and closer than via Hugo,but still with very realistic piano timbre. At times  and with some albums I had difficulty deciding which is really the better and  most transparent of the two via Sennheiser's equally superb HD800S.But it seemed that Hugo still does  percussion timbre and decay a bit more convincingly than Mojo judging from some works  where I have the real live reference .
But on 2L's Grieg album where I was present at the sessions and even stood among the players string tone had  a realism and grunge-free purity that challenged my Hugo.
No conventional sabre DAC based product I have heard sounds as good and realistic on those difficult to reproduce strings as Hugo and Mojo imo.
 
 
I need more time and a more quiet environment  than the  at times very  busy shop,to come to  absolutely clear and  safe conclusions. But one thing is clear, wow!
But I  still do wish you had included at least a proper headphone jack on Mojo.
The need to use an adapter on the flimsy litte mini jackport sometimes lead to channel drop-outs if I moved even a little.
I  wish that there will be a Hugo MK 2 PRO where all such  known problems and/or  market survey based compromises of both Hugo and Mojo have been ironed  out and solved.
 
Feb 11, 2016 at 8:12 AM Post #11,120 of 42,765
 
 
I am using my Mojo as my portable and home use. I would say galvanic isolation is not a need, the power line and data line is already split unlike the Hugo and there is the option to use optical cable with PC and laptops.
 
I have no issues using my Mojo with USB from my PC and have ordered an optical cable to see if there is going to be any real improvements.
 
At this price point, if you spilt up the same money and get a desktop DAC and another one for portable use. I don't even know if you can get one with galvanic isolation, let alone similar quality. I guess you are just worrying too much.


Hugo does not take power through either of it's USB ports.


My bad, gonna correct that to not cause confusion.
 
Feb 11, 2016 at 8:50 AM Post #11,121 of 42,765
  The problem with galvanic isolation is that the USB decoder chip and the data transmitter is powered from the mobile phone. There is no point in having 8 hours on Mojo if your mobile phone battery is depleted earlier. That said, you really need isolation when using a PC; its an order of magnitude smaller problem when using mobile phones, as everything is battery with no ground loops, and mobiles are incredibly power efficient compared to PC's - which gives you very much lower RF noise.

With this being the case, what would you recommend to help isolation when using a laptop that's plugged into the wall most of the time. I use my Mojo at work and have a dedicated machine just for my music listening purposes. 
 
Also, what would you recommend in terms of when to charge  or use the device while charging? Is it safe to charge while listening without causing problems to the battery? or is it better to let it drain and charge while not in use?
 
Feb 11, 2016 at 9:22 AM Post #11,122 of 42,765
  With this being the case, what would you recommend to help isolation when using a laptop that's plugged into the wall most of the time. I use my Mojo at work and have a dedicated machine just for my music listening purposes. 
 
Also, what would you recommend in terms of when to charge  or use the device while charging? Is it safe to charge while listening without causing problems to the battery? or is it better to let it drain and charge while not in use?

We are hearing good things about Audio Quest jitter bug - I have heard it stops the mobile phone EMC problems that can happen with Mojo and certain headphones. I will be checking it out soon.
 
Yes you may listen and charge at the same time. If you have access to power, its best to start charging as soon as possible, as internal power dissipation is lower with battery on blue than on red, so it will run less warm.
 
The battery is specified as a high temperature battery, and I charge at only 25% charging capacity - this is so it will work with 1A USB's, so no worries about battery life when charging.
 
Rob
 
Feb 11, 2016 at 9:56 AM Post #11,124 of 42,765
Anyone interested in the Audio Quest Jitter Bug ABT has it on sale right now for $40 and free shipping.
http://www.abt.com/product/93265/AudioQuest-JitterBug-USB-Data-Power-Noise-Filter-JITTERBUG.html
 
Feb 11, 2016 at 10:08 AM Post #11,125 of 42,765
  my god, i have been away from this thread for about a week and the post count was 1,200+
 
this has to be the fasted growing thread in headfi?

 
 
LOL - you should've been here 6 weeks ago - it was even faster, but yeah, it still runs away if you don't keep on top of it regularly
beerchug.gif

 
Feb 11, 2016 at 10:52 AM Post #11,126 of 42,765
With my cheap Optical cable, it struggles to get lock on 192kHz and only go up to 96kHz. I guess I have to spend a bit more?
 
Feb 11, 2016 at 11:14 AM Post #11,127 of 42,765
For those looking for a high-quality cost-effective (yeah, a relative statement) toslink cable, consider this one, below.

I have zero affiliation with the company, have no financial interest at all.

I cannot offer any opinion about the cable's performance; read about it yourselves.

It is glass, looks to be well-made, seems to come from a reputable manufacturer, and it feels very nice to hold and bend in one's hand.... Extremely pliable... But that could be due to the shielding for all I know.

My engineering son who has studied lasers tells me that many factors go into the efficient and effective transmission of data along an optical cable.

http://www.audioasylum.com/audio/cables/messages/15/153637.html
 
Feb 11, 2016 at 11:49 AM Post #11,129 of 42,765
  With my cheap Optical cable, it struggles to get lock on 192kHz and only go up to 96kHz. I guess I have to spend a bit more?

Yep. That's IME the biggest difference in the cables is the ability to achieve and keep the 192kHz lock. No problems with my 5mm Sys Concepts cable. Cheers 
 
Feb 11, 2016 at 11:58 AM Post #11,130 of 42,765
Hope to get my mojo back soon, never thought I'd miss an inanimate object.

What was wrong with it?
 
Guys, what is the logic for the up side down micro USB socket on the Mojo as it means that all control buttons are difficult to access as they are underneath i.e. resting on the table when using it as a desktop DAC?
cool.gif
 
 

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