Chord Mojo DAC-amp ☆★►FAQ in 3rd post!◄★☆
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hifinoob005

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I would also not leave it connected with the Mojo off.
LiPo batteries dont like being kept at full charge and don't like high or low temperatures.

for signal cables I'd generally try to keep them short. Charging cables should not be an issue.
Unfortunately the distance from USB to DAC is about 1.2/1.5m (4-5ft). Anker cables don't come in those sizes, 1m/3ft or 1.8m/6ft.
I tested using a 1.8m Hama shielded cable and it was fine.

Is a 1.8m cable ok?
I have to do some moderately serious reorganizing to accommodate a shorter cable.
 
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CaptainFantastic

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Has anyone else encountered this:

1. Mojo bought October 2019.
2. Runs perfectly, no issues until #4 below.
3. I plugged it in around 10h30 or 11h to charge via the very short included USB cable. Plugged USB A to laptop.
4. At 15h30 the white light is still on, so still charging. I suddenly hear a continuous whizzing electric noise, audible in my office. It's coming from the Mojo. I unplugged it after a few seconds not sure if it would get worse, catch fire, etc.

The unit was OFF the whole time. Still off.

Has anyone else experienced this?
 
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post-15343475
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jarnopp

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Has anyone else encountered this:

1. Mojo bought October 2019.
2. Runs perfectly, no issues until #4 below.
3. I plugged it in around 10h30 or 11h to charge via the very short included USB cable. Plugged USB A to laptop.
4. At 15h30 the white light is still on, so still charging. I suddenly hear a continuous whizzing electric noise, audible in my office. It's coming from the Mojo. I unplugged it after a few seconds not sure if it would get worse, catch fire, etc.

The unit was OFF the whole time. Still off.

Has anyone else experienced this?
That whizzing/whining noise is common and goes back to the beginning of this thread. It’s nothing to worry about and it usually occurs towards the end of the charge cycle, so maybe like the last 10-15 minutes it will be loudest.
 
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ohcrapgorillas

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I own the xDuoo X10T II and I have spent a lot of time going back and forth between coax and optical. They are very nearly identical, but it's true that the optical input is just slightly more focused than coax, whereas coax is a little warmer/fuller due to having just slightly less focus. They are close enough that I wouldn't worry about one or the other. I mostly use coax because the optical cable is kinda a PITA (have to carry around those little toslink connector protection caps, sensitive to bending in my pocket). Honestly the biggest reason I use coax is that the two units stack more neatly with the coax cable vs optical. The difference is small enough that I'd rather have the convenience. Mojo sounds so fantastic with the xDuoo as a source, it's hard to be unhappy even listening over USB, which to me sounds a bit brighter and has a tendency to become more congested during busy passages.

Note that to use the xDuoo with Mojo's optical input, you'll need a different cable than the stock one supplied with the unit, or do what I do and just get a mini toslink to regular toslink adapter.
 
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hifinoob005

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I own the xDuoo X10T II and I have spent a lot of time going back and forth between coax and optical. They are very nearly identical, but it's true that the optical input is just slightly more focused than coax, whereas coax is a little warmer/fuller due to having just slightly less focus. They are close enough that I wouldn't worry about one or the other. I mostly use coax because the optical cable is kinda a PITA (have to carry around those little toslink connector protection caps, sensitive to bending in my pocket). Honestly the biggest reason I use coax is that the two units stack more neatly with the coax cable vs optical. The difference is small enough that I'd rather have the convenience. Mojo sounds so fantastic with the xDuoo as a source, it's hard to be unhappy even listening over USB, which to me sounds a bit brighter and has a tendency to become more congested during busy passages.

Note that to use the xDuoo with Mojo's optical input, you'll need a different cable than the stock one supplied with the unit, or do what I do and just get a mini toslink to regular toslink adapter.
But why is the optical different sounding from the coaxial?

I don't have a coaxial output, but I can get a optical to coaxial converter. Currently the optical source is the Xonar.

The other option would be an adapter from the SPDIF OUT on the mobo, which will have a optical and coaxial outputs.

Will the converted coaxial (from the Xonar optical) sound different from the coaxial from the mobo?
 
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ohcrapgorillas

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As to why they are different sounding, I'm not really sure. The two technologies are pretty different, electrical vs optical that is, even though they are both S/PDIF. I have no idea what your motherboard's or the Xonar's digital output sounds like, but as I mentioned above, the coaxial and optical inputs on the Mojo are very close to indistinguishable (with my gear, ymmv), and I don't think it's worth getting nervosa over which one you're using. If I had to hazard a wild guess, the Xonar is probably a pretty decent transport. Personally, I would avoid getting an optical to coaxial or vice versa converter, which is more likely to add noise than it is to improve anything. You might try switching back and forth between the Xonar's optical and the mobo's coaxial/toslink and see (1) if you can tell the difference at all, and (2) which one you prefer.
 
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dgozalie

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Optical : zero electrical/magnetic/whatever interference... its a light...
coaxial: cable which can pick up interference from electrical/magnetic etc etc.. so might alter the signal...

Rob Watts said he prefer using optical over anything... so the designer of chord should know more than us ?
 
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CaptainFantastic

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Optical : zero electrical/magnetic/whatever interference... its a light...
coaxial: cable which can pick up interference from electrical/magnetic etc etc.. so might alter the signal...

Rob Watts said he prefer using optical over anything... so the designer of chord should know more than us ?
So how does one do optical from a phone as source? This is a unit for portable use, I imagine most have a different desktop solution. Is there an adapter allowinf phone to Mojo via optical?
 
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Slaphead

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But why is the optical different sounding from the coaxial?

I don't have a coaxial output, but I can get a optical to coaxial converter. Currently the optical source is the Xonar.

The other option would be an adapter from the SPDIF OUT on the mobo, which will have a optical and coaxial outputs.

Will the converted coaxial (from the Xonar optical) sound different from the coaxial from the mobo?
The same reason that USB connections can sound different from optical.

Optical is immune to EM interference. Electrical connections like USB and Coax aren't, and while they bring the data intact they also bring any EM interference along for the the ride.

Now this interference permeates through any audio device that isn't galvanically isolated, like the Mojo isn't, and thus can find its way to the analogue outputs.

Funnily enough this EM interference in a lot of cases can make the sound a bit more lively, with seemingly increased transient response, but when listening closely it lacks detail, or more to the point the detail is masked compared to the optical inputs.

But really this varies depending on your environment. Some people may hear the difference as clear as day, while others hear no difference, and those that hear a significant difference are likely to be listening in an electrically noisy environment.
 
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miketlse

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The same reason that USB connections can sound different from optical.

Optical is immune to EM interference. Electrical connections like USB and Coax aren't, and while they bring the data intact they also bring any EM interference along for the the ride.

Now this interference permeates through any audio device that isn't galvanically isolated, like the Mojo isn't, and thus can find its way to the analogue outputs.

Funnily enough this EM interference in a lot of cases can make the sound a bit more lively, with seemingly increased transient response, but when listening closely it lacks detail, or more to the point the detail is masked compared to the optical inputs.

But really this varies depending on your environment. Some people may hear the difference as clear as day, while others hear no difference, and those that hear a significant difference are likely to be listening in an electrically noisy environment.
I think my tests/experience aligns with this.
Back in the days when I only had the Mojo, I tested some baroque music (I think it might have been the tallis scholars recorded in a church) using both usb and optical inputs. Both resulted in clean music, but the usb input was slightly brighter, and at the time I attributed this to making me feel like I was actually at the recording.
A few months later i deliberately attended a choir singing baroque music in a church, accompanied by a lute. I discovered that in real life, the performance was a good match for music via the optical input - the usb input with a hint of brightness, sounds attractive but it is not a good match for the original recording.
Since then, I almost exclusively use optical input for my Mojo and Hugo 2.
But I also learnt a lesson, in that both usb and optical inputs can sound enjoyable, so i don't harshly judge anyone who prefers usb input, but I will always suggest owners try optical input because that for most setups is nearer to reality. But if an owner prefers usb, so be it, because that is personal preference.
 
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CJG888

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Frankly, I would have thought the primary benefit of Toslink would be the galvanic isolation of the Mojo from a potentially “dirty” laptop USB bus. Many laptops (e.g. Apple) have an optical output.
 
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CJG888

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The use case of a portable device with a clean coax output (and, being a portable, a short cable) is fairly unusual, I would have thought...
 
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Sound Eq

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As any competent DAC designer should, Rob has tried to minimise the influence of RF on his DAC designs.

However, the first remark you emboldened above, in the quoted text from Rob Watts, mentions a preference for optical. In relation to Mojo and RF, optical is ideal because an optical cable cannot act as an aerial capable of inadvertently picking up RF. Of course, RF may still attempt to get in directly through Mojos casework, even when optical is the chosen digital connection, but it should be vastly more difficult for RF to interfere with Mojos circuitry than in the scenario of a metal-conductor cable as would be the scenario with USB or Co-Axial.


In any event, the issue of RF and Mojo primarily relates to the potential influence of RF noise on the analogue circuitry (and many customers do not experience RF issues).
i want to comment on the RF issue again, as its a buzz killer for iem users who use tidal via wifi with there phone. This is the worst dac/amp I own that has this issue, i adore mojo sound but with its bad RF interference no one should recommend it for iems and users who use streaming using their phones. I am surprised Chord did not take this in consideration, as this is a portable device and portable means alot would like to use it with iems and streaming. Is there no solution at all for this
 
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