[miketlse]

 
Thank you for your reply, miketise. There is no change in bitrate occurring since the indicator on the Mojo remains the same color. Perhaps the OTG cable I'm using is the culprit, I don't know. I don't have another micro to micro USB cable to confirm.
 
Some insight from Chord would be very helpful ...

Are all your files being played from the 240SS?

 

[citraian]

Please read very carefully - this is not flippant advice - every single detail may be important and may be the clue to get your Mojo charging successfully. Just one little overlooked thing, may be the difference between frustration or success

Yes, did that as well. Thank you for all your effort

Noticed another strange thing today.
Mojo was fully charged in off state. I turned it on for 6 hours and the charging light was solid throughout the period (not blinking). When I turned it off after 6 hours it started blinking - can't understand why...

 

[jwbrent]

  Are all your files being played from the 240SS?

 
Yes. My next step is using my MacBook as my source, but I have to download my DSD files onto it first, and dealing with Android File Transfer is a major pain in the ass.
 
I may have found the culprit, more to follow ...

 

[jwbrent]

It appears the reason why I was having some difficulties with DSD albums is gapless playback on my 240SS. Some of my DSD albums are sensitive to this feature and cause the hiss emanating from my Mojo. When I turned off gapless everything worked fine.
 
No need for Chord to comment anymore.

 

[Mython]

 

Please read very carefully - this is not flippant advice - every single detail may be important and may be the clue to get your Mojo charging successfully. Just one little overlooked thing, may be the difference between frustration or success

Yes, did that as well. Thank you for all your effort

Noticed another strange thing today.
Mojo was fully charged in off state. I turned it on for 6 hours and the charging light was solid throughout the period (not blinking). When I turned it off after 6 hours it started blinking - can't understand why...

 
 
That is because, with some current-hungry transducers, or with some chargers, there may be a slight net-discharge of the battery, during playback, even when the charger is plugged-in, especially if the charger is one that throttles its power output to a trickle when it believes Mojos battery has a high percentage of charge.
 

 

  Yes of course @Mython. However it doesn't describe what state the Mojo is in does it? Playing, off, on but not playing.
 
He is talking about when there is no net charge on the battery. I am talking about when the battery level has dropped and when it needs a bit of charge. (While charging and playing, from a full battery.)
 
To be honest though I have probably over looked a simple principle of electronics and should know better.

To understand it better, let's assume Mojo is off and charging.
 
Now the charger has two modes of normal operation - constant current, which is set to 330 mA, and constant voltage which is set to 8.200 V. Now when the non charging battery battery voltage is less than 8.200 V, then the charger supplies a constant current. But when the non charging battery voltage gets close to 8.200 V, then the charger switches mode to constant voltage at 8.200 V. The current that is charging the battery then slowly falls from the initial 330mA, to zero - its in the trickle charge mode now. Eventually, the non charging battery voltage hits exactly 8.200 V, the charger is in constant voltage mode of 8.200 V, no current now flows into the battery, and the charger switches off automatically. When the battery voltage falls to 8.0 volts, then the charger will return to charging. Tip - if you want to force the charger to top up Mojo's battery to 8.200 V then removing the charge USB, wait 5 seconds, reattach, and the charger will top it up to 8.200 V.
 
Now imagine that Mojo is on at the same time as it is charging. In this case, the battery will continue to charge until it gets to 8.200 V, and the charger is set to voltage mode and gives 8.200 V too; so no current flows into or out of the battery; but Mojo itself is drawing 180 mA of DC current, and this will simply come from the charger - so the charger will supply the needed 180 mA for Mojo. It will do this for ever, and it won't switch off. This is intended, as it means that the battery is effectively not being used to supply the bulk of the current, won't charge or discharge, is held at a safe level, and will operate like this for a very long time.
 
Now we have been talking about DC currents, and this is indeed the vast bulk of the current. But what about dynamic currents and noise? Because the output impedance of the battery is much lower than the charger, then the noise of the charger is reduced; also dynamic currents still comes from the battery. So running in this mode ensures the best of both worlds - low RF and audio band noise from the battery, large dynamic currents available, and low PSU impedance too - but without the worry of the battery wearing out from charge and discharge cycles.
 
I hope this clarifies.
 
Rob 

 
 

when the Mojo is being used and being charged especially when driving lower impedances there is a net drain on the battery. This means that the charging circuit does not quite provide enough power to power the Dac and amp circuitry and keep charge the battery at the same level this is because we had to limit the amount of charge over a given time due to thermal constraints. Our charging time with the Mojo switched off is usually four or max five hours this is a little inconvenient but when we compare this to other Dac amps that need up to a full twenty four hours to charge we feel that we didn't do such a bad job.

 

[citraian]

That is because, with some chargers, there may be a slight net-discharge of the battery, during playback, even when the charger is plugged-in, especially if the charger is one that throttles its power output to a trickle when it believes Mojos battery has a high percentage of charge.

I'm not sure that I understand. My uncertainties were related to the fack that the light started blinking right after I turned it off... Using a dumb charger at the moment...

 

[Mython]

 

That is because, with some chargers, there may be a slight net-discharge of the battery, during playback, even when the charger is plugged-in, especially if the charger is one that throttles its power output to a trickle when it believes Mojos battery has a high percentage of charge.

I'm not sure that I understand. My uncertainties were related to the fack that the light started blinking right after I turned it off... Using a dumb charger at the moment...

 
 
Ah, OK, apologies - I misread your post (distracted with other things, here!), sorry (but I'll let the above remain, as it's of related interest).
 
 
 
Thinking about possibilities for the behaviour you described, what if Mojo was not receiving sufficient current from the charger, during playback, such that it just used it's own battery, and then, when switched-off, after 6 hours use, the battery needed charging but couldn't receive sufficient current from the charger?
 
We're going round and round in circles with your issue - you say you've changed your charger to a 'dumb' one - are you certain (I mean really certain) you've tried a different charging cable, too? Some cheap cables just resist the current too much.

 

[citraian]

Ah, OK, apologies - I misread your post (distracted with other things, here!), sorry (but I'll let the above remain, as it's of related interest).



Thinking about possibilities for the behaviour you described, what if Mojo was not receiving sufficient current from the charger, during playback, such that it just used it's own battery, and then, when switched-off, after 6 hours use, the battery needed charging but couldn't receive sufficient current from the charger?

We're going round and round in circles with your issue - you say you've changed your charger to a 'dumb' one - are you certain (I mean really certain) you've tried a different charging cable, too? Some cheap cables just resist the current too much.

No problem
Really strange behavior - it seemed to receive enough power since in the 6 hours that it was on the light remained lit for the entire duration. Also, when I turned it off and noticed that the light started blinking I replugged the cable and the light remained lit...

I'm using a dumb 2A charger and an Audioquest Cinnamon cable at the moment for troubleshooting. Can't imagine that this setup is so resistive to get under 1A...

Yes, I feel like I'm running in circles here as well, banging my head with every info or solution that I can find, all to no avail. It was all working perfectly for a few months and then it decided to act out on its own. Waiting for an USB tester to come, maybe that will shed some light.

 

[Mython]

Do you at least have the original short USB cable that came included with Mojo?

 

[Mython]

  it seemed to receive enough power since in the 6 hours that it was on the light remained lit for the entire duration. Also, when I turned it off and noticed that the light started blinking I replugged the cable and the light remained lit...

 
 

  .... one of the safety circuits is a safety timer, and this is when the charger is in full charge mode. This timer is set to about 8 hours, and normally full charge mode takes 4 hours, when the unit is off. But when the unit is on and playing, there is a risk that the safety timer will be set, as it can take 12 hours to fully charge (from flashing red) and when playing music (for those 12 hours) at the same time.
 
If the safety timer is set, then the battery LED will slowly flash white, and no further charging will take place. To reset the timer, just disconnect the charge USB, wait 10 seconds, and reconnect, and it will recommence charging. So if you are charging and playing, then when you have finished listening, turn Mojo off, and it will be OK. When Mojo is blue, and you connect the charger, then it is trickle charge mode, and the safety charger is not operating. So if Mojo is green, the safety timer won't trip out, as it will play and leave full charge mode within 8 hours, so you will be OK. It should be OK at yellow too. I guess the easiest way of dealing with it is to turn Mojo off after listening, then you will be fine, unless you listen for longer than 8 hours starting from fully flat.
 
Note that you can get the flashing battery LED if the USB charger voltage is low, from a charger that can't supply the current, or a USB cable that has high resistance. But you will see this pretty early on.
 
I hope this clarifies.
 
Rob

 

[citraian]

Do you at least have the original short USB cable that came included with Mojo?

I do, unfortunately that's too short :| Tried an Anker cable though...

Also, I don't think that what happened today was related to the safety timer as Rob says that it hits after 8 hours and not 6 like it was in my case. I don't think it was a coincidence - the charging light started blinking as soon as I turned the Mojo off, no sooner, no later...

 

[Mython]

Even if the short USB cable is inconvenient for you, please just try it, temporarily, for troubleshooting purposes.
 
You/we need to make some progress with this issue, for the sake off everyone's sanity

 

[citraian]

Even if the short USB cable is inconvenient for you, please just try it, temporarily, for troubleshooting purposes.

You/we need to make some progress with this issue, for the sake off everyone's sanity :wink_face:

The short cable is not just inconvenient, I'm past inconvenient at this point. It's just too short to get to the charger. I'll try to think of a solution to get the charger closer though I don't get why a product would work perfect for a long time and then just decide to need its original short cable.

 

[Mython]

 

Even if the short USB cable is inconvenient for you, please just try it, temporarily, for troubleshooting purposes.

You/we need to make some progress with this issue, for the sake off everyone's sanity

The short cable is not just inconvenient, I'm past inconvenient at this point. It's just too short to get to the charger. I'll try to think of a solution to get the charger closer though I don't get why a product would work perfect for a long time and then just decide to need its original short cable.

 
You are welcome to troubleshoot differently, if you prefer.
 
What do you propose instead?

 

[citraian]

You are welcome to troubleshoot differently, if you prefer.

What do you propose instead?

I just don't get how 3 different cables and 3 different chargers could cease to work at the same time even if they worked properly before. Especially cables... Don't get me wrong, I don't want to seem rude.

As said previously I hope to get an USB tester ASAP so that I can measure exactly what happens on the charging side.