[surfgeorge]

Just checking, I've searched and it seems the only way to switch inputs from USB to toslink is to unplug the USB and restart the Mojo is that right? I'm using the Mojo for PC and TV input, battery has been unplugged, I'm just using it as a desktop setup.

And it looks like there were no firmware updates for the Mojo? (Short press switch inputs would be nice heh)

AFAIK you do not need to restart the Mojo.
It scans the inputs and automatically connects. If there are several inputs connected in parallel the USB has priority, then I think coax and last optical.
I have definitely switched between inputs without restarting

 

[miketlse]

Just checking, I've searched and it seems the only way to switch inputs from USB to toslink is to unplug the USB and restart the Mojo is that right?

No. The Mojo checks for the 5V signal on the VBUS pin of the USB. If 5V is present, then USB input is autoselected. Removing the cable removes the 5V, and USB will be deselected. No need to reboot the Mojo.

 

[Pocomoto]

Hello, First post. I use my Mojo mainly as a system DAC, but also with HD650 headphones. When the battery died, rather prematurely I thought, (may have been my charging technique), I got an AliExpress small battery and fitted it. However it runs out of juice very quickly even with charger left on.

My question is could I connect a 6.3V Lead Acid battery (I have a very large one) to the internal pins in place of the internal battery. I understand that fancy power supplies are not approved, but a large 6.3V 110 AH telecoms battery seems a good replacement. . The Mojo battery is 7.2V but the big battery will run up to 7.1V on full charge. Will the Mojo run on 6.3V?

I would not connect the usb charger.

I will have to drill the Mojo case but I'm not planning to sell it. Or take it anywhere. I am a certified audio diy nut but have lots of mileage.

Thank you for any advice.

 

[Kentajalli]

Hello, First post. I use my Mojo mainly as a system DAC, but also with HD650 headphones. When the battery died, rather prematurely I thought, (may have been my charging technique), I got an AliExpress small battery and fitted it. However it runs out of juice very quickly even with charger left on.

My question is could I connect a 6.3V Lead Acid battery (I have a very large one) to the internal pins in place of the internal battery. I understand that fancy power supplies are not approved, but a large 6.3V 110 AH telecoms battery seems a good replacement. . The Mojo battery is 7.2V but the big battery will run up to 7.1V on full charge. Will the Mojo run on 6.3V?

I would not connect the usb charger.

I will have to drill the Mojo case but I'm not planning to sell it. Or take it anywhere. I am a certified audio diy nut but have lots of mileage.

Thank you for any advice.

No. I believe it cuts out at anything below 7V.
Mojo battery maybe rated as 7.4V but in reality it hovers more than that (about 8V). Lead-acid battery under charge is about 6.9V.
There is a battery on Aliexpress that works fine. I am using one and atleast one more member is using it successfully. on my first attempt I got 9 hours on USB.
You can always contact CHORD and get an official battery too.
Don't risk damaging the circuit board, just get a battery.

https://www.head-fi.org/threads/chord-mojo-dac-amp-☆★►faq-in-3rd-post-◄★☆.784602/post-16584559
https://www.head-fi.org/threads/chord-mojo-dac-amp-☆★►faq-in-3rd-post-◄★☆.784602/post-16554028

 

[Pocomoto]

No. I believe it cuts out at anything below 7V.
Mojo battery maybe rated as 7.4V but in reality it hovers more than that (about 8V). Lead-acid battery under charge is about 6.9V.
There is a battery on Aliexpress that works fine. I am using one and atleast one more member is using it successfully. on my first attempt I got 9 hours on USB.
You can always contact CHORD and get an official battery too.
Don't risk damaging the circuit board, just get a battery.

https://www.head-fi.org/threads/chord-mojo-dac-amp-☆★►faq-in-3rd-post-◄★☆.784602/post-16584559
https://www.head-fi.org/threads/chord-mojo-dac-amp-☆★►faq-in-3rd-post-◄★☆.784602/post-16554028

OK thanks, I saw that, I'll get one. What is the correct way to preserve battery life? And initially charge. Any links? I have read stuff here before but forget where. Battery memory etc.

 

[Kentajalli]

OK thanks, I saw that, I'll get one. What is the correct way to preserve battery life? And initially charge. Any links? I have read stuff here before but forget where. Battery memory etc.

There is no memory issue with LiPo's.
Just fully charge it as standard.
If you continually let it drain fully, you shorten the life.
When it gets to yellow, or just red, charge it up again.
Since Ali's battery is not from CHORD, I suggest you do not charge it while you use it, as it generates good amount of heat, which I am uncertain how it would affect the unofficial battery.
Others have been using Mojo, without a battery as desktop DAC.
It evidently does not cause any damage.
I, however, have advised against it theoretically, but others swear by it!

 

[vlach]

Pocomoto,
You can use the Mojo without a battery as desktop DAC, just be aware that the charging circuit will remain ON if the Mojo stays connected to the 5V USB source, even after you power the Mojo OFF.
I realized this the other day when i hadn't used it for a couple days and noticed it was slightly warm to the touch. Now i just disconnect the USB cable when not in use.

Edit: As a desktop DAC you are essentially charging & playing, therefore the unit gets very hot but at least the battery is no longer getting cooked inside.

 

[Pocomoto]

Pocomoto,
You can use the Mojo without a battery as desktop DAC, just be aware that the charging circuit will remain ON if the Mojo stays connected to the 5V USB source, even after you power the Mojo OFF.
I realized this the other day when i hadn't used it for a couple days and noticed it was slightly warm to the touch. Now i just disconnect the USB cable when not in use.

Edit: As a desktop DAC you are essentially charging & playing, therefore the unit gets very hot but at least the battery is no longer getting cooked inside.

There is no memory issue with LiPo's.
Just fully charge it as standard.
If you continually let it drain fully, you shorten the life.
When it gets to yellow, or just red, charge it up again.
Since Ali's battery is not from CHORD, I suggest you do not charge it while you use it, as it generates good amount of heat, which I am uncertain how it would affect the unofficial battery.
Others have been using Mojo, without a battery as desktop DAC.
It evidently does not cause any damage.
I, however, have advised against it theoretically, but others swear by it!

Thanks Kentajalli, That is just what I wanted to know. Strange as I thought kept mine on full charge. Before I got it I would borrow my son's Mojo, and his is still going strong on same battery maybe 5 years now.. Maybe it runs down when not in use, there were periods I left it in the box while I played with other stuff.

 

[Pocomoto]

What can be drawing power when there is no battery inside to charge and the mojo is off? I guess there must be a DC-DC converter to step up the voltage from 5V usb to 7.2V ++ charging voltage. Is this it? Seems unlikely it would get warm.

The other thing I notice is the charger cannot keep up with the battery drain when the Mojo is playing music. So if you use the charger for music with no battery, what is the effect of the shortfall?

 

[vlach]

What can be drawing power when there is no battery inside to charge and the mojo is off? I guess there must be a DC-DC converter to step up the voltage from 5V usb to 7.2V ++ charging voltage. Is this it? Seems unlikely it would get warm.

The other thing I notice is the charger cannot keep up with the battery drain when the Mojo is playing music. So if you use the charger for music with no battery, what is the effect of the shortfall?

I think you're right about the DC-DC converter, at least i think that's what i read on this forum at one point but others can confirm.
No shortfall using the charger for playing music in DAC mode feeding an external amp or using IEMs but not ideal to drive heavier loads, like 300 or 600 ohm, less sensitive headphones, planars, etc.

 

[Pocomoto]

I'll give it a go, thanks. I kind of resigned myself to the fact it was meant for occasional use headphones, but the sound on my horn system is so 'Gloria hallelujah' compared to my hairshirt diy Amanero / TD1541 / tube DAC that I can't leave it alone.

You can't help thinking that a usb battery charger cannot be the ultimate in audio power supplies, but I guess just lie back and enjoy it. And / or cough up for a decent battery.

 

[vlach]

I'll give it a go, thanks. I kind of resigned myself to the fact it was meant for occasional use headphones, but the sound on my horn system is so 'Gloria hallelujah' compared to my hairshirt diy Amanero / TD1541 / tube DAC that I can't leave it alone.

You can't help thinking that a usb battery charger cannot be the ultimate in audio power supplies, but I guess just lie back and enjoy it. And / or cough up for a decent battery.

I think your previous thought of drilling a small hole in the Mojo enclosure and plugging in an external battery (an idea I'm considering myself) is probably the ideal solution to make the Mojo a desktop DAC and get the cleanest power source.
I'm just not 100% sure which battery voltage to use. I measured 8.4V for the fully charged internal battery,. I wonder if i could wire several 9V batteries in parallel, then i would be set for a long time before having to replace them.

Edit: Or maybe wire (5) large D size 1.5V batteries in series, that would be closer to the nominal rating of the internal battery.

 

[Pocomoto]

I think your previous thought of drilling a small hole in the Mojo enclosure and plugging in an external battery (an idea I'm considering myself) is probably the ideal solution to make the Mojo a desktop DAC and get the cleanest power source.
I'm just not 100% sure which battery voltage to use. I measured 8.4V for the fully charged internal battery,. I wonder if i could wire several 9V batteries in parallel, then i would be set for a long time before having to replace them.

Edit: Or maybe wire (5) large D size 1.5V batteries in series, that would be closer to the nominal rating of the internal battery.

7.2V is 6 x 1.2V so I would guess that the mojo battery is 6 x Lithium single cells in series. I see on AliExpress they sell a lot of 3.7V batteries. These presumably are made up of 3 x Lithium cells. You could series parallel four or more of these for a higher capacity.

Edit: It says here that a single Lithium ion cell is 3.7V. https://www.swe.com/lithiumion/ I was thinking of those AA batteries. presumably the 7.2V mojo battery is 2 x cells in series.

You might want to use an external charger however, so not to overload the built in device. You could then get a smart charger that prolonged battery life. See Battery University. Homework:

https://batteryuniversity.com/article/bu-204-how-do-lithium-batteries-work

 

[Pocomoto]

7.2V is 6 x 1.2V so I would guess that the mojo battery is 6 x Lithium single cells in series. I see on AliExpress they sell a lot of 3.7V batteries. These presumably are made up of 3 x Lithium cells. You could series parallel four or more of these for a higher capacity.

Edit: It says here that a single Lithium ion cell is 3.7V. https://www.swe.com/lithiumion/ I was thinking of those AA batteries. presumably the 7.2V mojo battery is 2 x cells in series.

You might want to use an external charger however, so not to overload the built in device. You could then get a smart charger that prolonged battery life. See Battery University. Homework:

https://batteryuniversity.com/article/bu-204-how-do-lithium-batteries-work

Reading the above under 'Limitations' I can see why mine failed:
"Degrades at high temperature and when stored at high voltage"

Prolonging life of
https://batteryuniversity.com/article/bu-808-how-to-prolong-lithium-based-batteries

Charging Li ion batteries
https://batteryuniversity.com/article/bu-409-charging-lithium-ion

 

[magicalmouse]

My mojo suddenly stopped working on usb - it works on coax but when connected to my win10 pc (win10 up to date) it stopped connecting.

I tried removing the latest win10 update but this made no difference, i changed usb connectors & tried everyone i had, different computers made no difference.

I uninstalled the chors drivers and the rebooted and reinstalled them.

I opened it up and cannot see any issue with the usb connectors, it still charges ok.

I wonder if there is some software issue i am no aware of.

Any ideas?

d