[AlexCBSN]

This battery discussion seems to come up again and again. At the end of the day I don't see why Chord does not make it easy and economical for Mojo owners to replace their batteries. It would be a win win, better experience for the customers, better product support and they are not giving the batteries away for free.

Actually I was about to ask @Kentajalli where did he got his from

 

[Kentajalli]

Actually I was about to ask @Kentajalli where did he got his from

From AudioAdvice for $43 each. They had two, I got them both.
They do not send to UK, so I had them sent to my daughter in California, and she sent them to me in UK.

 

[Hooster]

From AudioAdvice for $43 each. They had two, I got them both.
They do not send to UK, so I had them sent to my daughter in California, and she sent them to me in UK.

Perhaps it is due to the fact that they sell Chord products and therefore have a relationship with Chord. Could it be that Chord would prefer that people in the UK took their their Mojo to a dealer and fork out the full price of having a dealer change the battery? Is it possible that Chord isn't being particularly helpful to their "valued" customers?

 

[Kentajalli]

Perhaps it is due to the fact that they sell Chord products and therefore have a relationship with Chord. Could it be that Chord would prefer that people in the UK took their their Mojo to a dealer and fork out the full price of having a dealer change the battery? Is it possible that Chord isn't being particularly helpful to their "valued" customers?

I would not past them.
However, Audio Advice does not ship internationally - period! any brand , anything, and they do free shipping, perhaps that is the reason.
I tried high and low to get my hands on suitable batteries, non exist - unless you settle for very low quality, low power shoe-ins.
A manufacturer in China, who lists the battery's original cell, would manufacture - but 3000 pieces min. order (you need two cells per battery).
I believe the original batteries are made by a US company called CPS, they did not even reply to my email.
It is pandemic after all - I didn't expect much.

 

[surfgeorge]

2nd Update:
Recently I asserted that : we are not clever enough to re-engineer this device!
I am about to tell you what I have done in stark contrast to that statement, just for fun and for the heck of it.
While I had the Mojo opened up, I thought I do something about the Heat management within Mojo.
So with the circuit board loose on a towel, I connect everything up to see from where the heat comes from.
While playing most of the heat comes from the two large chips in the centre (the system/input chip and the FPGA gate array)



Warning first ; Be really carefull if you open it up, specially the click-buttons as their metal caps are only held in place with a tiny tape - I almost lost mine.
These chips are stuck to the underside of the battery, so they heat up, they transfer their heat to the battery, which is not a good idea - specially that their centers are the hot spots, so they heat up two spots on one side of one of the batteries. I thought I do something about that.
Next I connected the charger, to get the thing really hot!
Incidentally, the battery remains cool as a cucumber discharging or charging, so none of the heat is due to the batteries.
While charging, the circuit components on the underside of the board near the charging socket get really hot! enough to burn your finger if you keep it on it more than a few seconds. These components are sitting in an airgap (about 1-3 mm) above the bottom shell. They were next on my list.


The cluster of components on the left and centre can get really hot while charging.

Also the underside of the board where the large hot chips from otherside sit, also get hot - next item on the list.
So I carefully located these hot sections, and stuck 1.5mm and 2.5mm heat conducting pads on the bottom shell. these pads are widely used for cooling in computer systems.
This would thermally bond the hot components to the bottom shell, fairly easy.

To take the heat from the two large chips on the top away from the battery and to the shell to dissipate out, needed more effort.
So I cut a strip of pure copper sheet (17mm X 100mm X 0.5mm thick) and bent it into this shape.



It is so shaped so it would touch the tops of the chips, but avoid anything else on the circuit, the end wings have thin thermal pads attached to them, because ultimately they would be touching the inside of the top shell to pass the heat on. The two black pieces of sponge would press the copper to the chips to make a good contact.
Thermal pads are attached to the chips (0.5mm thick), and the copper heatsink is inserted on the top shell.



Lastly, a tiny amount of heatsink compound is applied to the top shell contact areas with the bottom shell, and the shells are brought together gently.



The foam inserts on the strip cause the shells to sit apart a few mm's - as I tighten the screws gently and in sequence, the shell would close up, squeezing a little paste out. no worries, it cleans up easily with white spirit and tissue paper.
The strip of copper is now sitting with a small airgap to the battery, hopefully it is cooling the chips and conducting the heat to the outer shells.
So what did it achieve?
- Mojo is a few grams heavier, not by much, but you can tell!
- Within a minute of switching on, the entire case starts to get warm, much faster than before, it may even feel like it is warming more, but it is not.
- Charging and listening at the same time, causes the case to warm up really quickly, I take this as a good sign. It means the heat is getting out quickly so it can dissipate faster, causing the final temperature equilibrium to be a few degrees lower. Provided you don't use a case, as it would nullify all this effort.
- Wonderfully the initial fizzing noise while charging is gone! I assume the thermal pads stop the buzzing components from vibrating. Mojo just goes into charge mode without making any noise.
- The entire shell is at same temperature, no hot spots.
- As I write this it has been playing for 3 hours straight, it is just warm to touch - Just!
- I believe the battery lasts a little longer, but I have not actually tested this.

Well I had fun doing it.

BTW - this is my DIY interconnect from my phone to Mojo.


It is about 750mm long, has a tiny USB hub and a MicroSD card reader soldered in the middle, two small ferrite cores at ends. The MicroSD card is 512GB, it holds my music. The phone detects both the card and Mojo through the same cable. Cable is super flexible 3mm X 2mm.

I really admire your courage and creativity, even ingenuity!
Well done! I hope Chord will learn from this and consider it in a Mojo 2
PS: are there any instructions for the cable with the micro-SD card? Another clever solution...

 

[Kentajalli]

I really admire your courage and creativity, even ingenuity!
Well done! I hope Chord will learn from this and consider it in a Mojo 2
PS: are there any instructions for the cable with the micro-SD card? Another clever solution...

Thank you, I appreciate that.
Since last night I have been running the Mojo to see how long the battery lasts.
So far it has done about 8.5 hours - still going, but the battery is flashing red, it surely lasts longer, next I test it to see how fast it charges up.
The current battery is about a year old.
Regarding the USB cable, see this
https://www.head-fi.org/threads/diy-cable-gallery.71148/post-15939991
It should explain how I did it - infact this is my second attempt. the issue is power usage!
SDcard readers tend to be power hungry, the phone is supplying the power. My first cable was drawing 100mA more than my current cable.
It is not much, but if you are on a train or a plane (fat chance these days), you probably get about 10 hours out of your phone instead of 15.
You need your phone when you land!!
just pushing the envelope - that's all.
BTW - my day job is working and repairing computers and laptops, which involves certain level of motherboard component level work, so to some degree I am used to it.

My first attempt:
https://www.head-fi.org/threads/diy-cable-gallery.71148/post-15932742

 

[118900]

4 more hours and my first (10 hour) charge will be complete and I too shall hear the dulcet tones of the mojo playing into my ears

 

[Dexter22]

Anybody in India interested in getting one locally? A friend of mine has one for sale. Looking for 27k including a leather case which costs around 9k. He just sold his speakers and wants to sell his mojo too to get higher end speakers. DM me if interested.

 

[118900]

Got to admit from a first 30 minute listen last night I was very very impressed. Clear similarities with the other chord Dacs I have or have had (H2 and HTT2) and going by memory and comparative notes quite close to the H2. Clearly better than my DFC which is admittedly cheaper and smaller so a different product.

really happy with it

 

[Dexter22]

Got to admit from a first 30 minute listen last night I was very very impressed. Clear similarities with the other chord Dacs I have or have had (H2 and HTT2) and going by memory and comparative notes quite close to the H2. Clearly better than my DFC which is admittedly cheaper and smaller so a different product.

really happy with it

There is nothing better than mojo under 500. Period. The closest in terms of perfomance to me was a ifi audio black label which costs more than mojo yet sounded artificial in comparison. Nothing beats a mojo.

 

[Kentajalli]

There is nothing better than mojo under 500. Period. The closest in terms of perfomance to me was a ifi audio black label which costs more than mojo yet sounded artificial in comparison. Nothing beats a mojo.

Here is a challenge for you.
I require a device, with at least:
- one usb input
- not much bigger than Mojo
- one headphone out
- similar battery life or better
- up to $1500 !
- better sound even slightly.
And if you should struggle to come up with anything, it's OK - I couldn't either! still looking though . . .

 

[CaptainFantastic]

Here is a challenge for you.
I require a device, with at least:
- one usb input
- not much bigger than Mojo
- one headphone out
- similar battery life or better
- up to $1500 !
- better sound even slightly.
And if you should struggle to come up with anything, it's OK - I couldn't either! still looking though . . .

You didn't say new. So... Hugo 2 not brand new but mint condition. I bought mine for under $1500 and it's absolutely great on all counts (like new condition, long battery life, amazing sound).

 

[Kentajalli]

You didn't say new. So... Hugo 2 not brand new but mint condition. I bought mine for under $1500 and it's absolutely great on all counts (like new condition, long battery life, amazing sound).

Is Hugo 2 similar in size and battery lasts as long?

 

[CaptainFantastic]

Is Hugo 2 similar in size and battery lasts as long?

Missed the size thing. Battery lasts longer but it's bigger. Nevermind then. But consider that the increase in sound quality is nowhere near "slightly better", it is considerably better.

 

[118900]

Missed the size thing. Battery lasts longer but it's bigger. Nevermind then. But consider that the increase in sound quality is nowhere near "slightly better", it is considerably better.

I think the jump from H2 to HTT2 is noticeably larger than the jump from the mojo to the H2 which was unexpected considering the law of diminishing returns.

based on my listening notes made in preparation for the change from the H2 to the HTT2 and from memory (admittedly fallible) the mojo comes very close to the H2. I don’t know how much it matters but there are only 15K taps between the mojo and H2 but a full 50K taps between the H2 and the HTT2, plus several other gizmos such as the super capacitors.
Either way I think in their respective classes they are all incredible products.