[Kentajalli]

Apologies necro'ing this thread
@Kentajalli, I've had my mojo running directly off of the 5V usb input with no battery for some time - it became a desktop DAC when the pandemic hit.
I now have it in my living room and would like it to stay on at all times, as it shuts off eventually with the 5V input. I have a 9V power supply and the correct terminals to direct wire, bypassing the charging circuit. Am I correct to believe this would keep the Mojo running 24/7? If so, would this be an ideal diode to wire inline with the positive feed?
Additionally, forgive the list of questions, but if I was to add a capacitor to pull out additional noise, where would the ideal connection points be?
Thanks in advance... I have plenty of soldering experience but limited knowledge of circuitry.

I think it shuts down, because it senses no music! I don't think it has anything to do with powersupply.
You can test this, put something to play in a loop, so there is always something to play, to see if your mojo shuts down.
First try that, before you get into nitty gritty!

 

[onelivewire]

Hmm... I've had it shut off during regular play on desktop from time to time, so I assumed there was also a long-term timer of some sort (and doubted it was thermal protection, as I've had it run fine on very hot days outdoors). I had also read that the USB input did not have the music shutoff feature. Perhaps I'm mistaken?
Given that I have the supplies, sans the diode, I'm still interested in making the change, but maybe it won't solve for the on/off issue?

 

[MohiJo]

Reviving this thread since out there are many Mojos to be freed of enslaved battery life.

For me the reason is that the Mojo played much better than certain recent, modern delta-sigma DAC with perfect measurements!
Both were fed from Innuos Phoenix USB via short Curious Evolved USB cable.
So i want to get rid of battery and make Mojo a permanent DAC.

Is there some concensus about 8.3V being the ideal voltage for Mojo, given that the majority of its users never heard it at that voltage? And what does this mean in terms of sound compared with e.g. to 7.5V or 8V?

 

[miketlse]

Reviving this thread since out there are many Mojos to be freed of enslaved battery life.

For me the reason is that the Mojo played much better than certain recent, modern delta-sigma DAC with perfect measurements!
Both were fed from Innuos Phoenix USB via short Curious Evolved USB cable.
So i want to get rid of battery and make Mojo a permanent DAC.

Is there some concensus about 8.3V being the ideal voltage for Mojo, given that the majority of its users never heard it at that voltage? And what does this mean in terms of sound compared with e.g. to 7.5V or 8V?

If you are referring to the battery voltage, then 8.2V should result in a longer battery life than 8.3V.

However if you are removing the battery anyway, you can experiment a bit.
https://www.head-fi.org/threads/chord-mojo-dac-amp-☆★►faq-in-3rd-post-◄★☆.784602/post-16213173

 

[Kentajalli]

Reviving this thread since out there are many Mojos to be freed of enslaved battery life.

For me the reason is that the Mojo played much better than certain recent, modern delta-sigma DAC with perfect measurements!
Both were fed from Innuos Phoenix USB via short Curious Evolved USB cable.
So i want to get rid of battery and make Mojo a permanent DAC.

Is there some concensus about 8.3V being the ideal voltage for Mojo, given that the majority of its users never heard it at that voltage? And what does this mean in terms of sound compared with e.g. to 7.5V or 8V?

I don't know where you got the 8.3V from.
The LiPo batteries used, at 100% charge, reach 8.4V, however, Rob Watts, had the foresight to design the charging circuit to cut out at 8.2V. This was purely to give the batteries a longer life. The voltage from 7V to 8.2V has almost no bearing on sound quality. I believe the device cuts out at 6.9V.
The only difference, the extra voltage (from 7V to 8.2V makes, is the max power output, as the device will not be able to swing as much, so you miss a little max voltage swing, that's all.
The batteries, while in situ, provide extra smoothing, and better instantaneous current surge.
The charging circuit inside the Mojo classic, was not designed to supply power to the mojo to be used in desktop mode (there is no desktop mode!), it was just a charging circuit. That having been said, there are those who have done exactly that and swear by the results (just scroll up), but technically the fact is that, the mojo classic deserves better.
On Mojo2, Rob watts (probably because of such feedbacks from Headfi) upgraded the powersupply section, so that, it, indeed, can supply enough power to Mojo2 (clean power) and also keep the battery trickled charged at a point to maximize its life span.
If the original PSU on Mojo classic was sufficient, then Rob Watts has sort of, wasted his time and Chord's money to upgrade it! Ask yourself that . . .

 

[MohiJo]

I don't know where you got the 8.3V from.
The LiPo batteries used, at 100% charge, reach 8.4V, however, Rob Watts, had the foresight to design the charging circuit to cut out at 8.2V. This was purely to give the batteries a longer life. The voltage from 7V to 8.2V has almost no bearing on sound quality. I believe the device cuts out at 6.9V.
The only difference, the extra voltage (from 7V to 8.2V makes, is the max power output, as the device will not be able to swing as much, so you miss a little max voltage swing, that's all.
The batteries, while in situ, provide extra smoothing, and better instantaneous current surge.
The charging circuit inside the Mojo classic, was not designed to supply power to the mojo to be used in desktop mode (there is no desktop mode!), it was just a charging circuit. That having been said, there are those who have done exactly that and swear by the results (just scroll up), but technically the fact is that, the mojo classic deserves better.
On Mojo2, Rob watts (probably because of such feedbacks from Headfi) upgraded the powersupply section, so that, it, indeed, can supply enough power to Mojo2 (clean power) and also keep the battery trickled charged at a point to maximize its life span.
If the original PSU on Mojo classic was sufficient, then Rob Watts has sort of, wasted his time and Chord's money to upgrade it! Ask yourself that . . .

Thnx for your reply, this clarified everything!

I want to skip battery and use a LPSU.
So 1st what came to my mind was Farad Super3 LPSU, cos it is closest to the battery - it uses super capacitors! When you switch it on for the 1st time, it even takes like 30 seconds to charge them, and then your good to go.
Also voltage can be set as required. I will probly go with 8V since it does not require any special adjustment.
So i will use only one DC cable from PSU all the way to the JST (molex) connector in the Mojo upon which i will drill a hole.

I think the upgraded Mojo2 PSU is in the 1st line to get rid of playing broken by charging, which is disturbance factor #1 for me. Plays for like 5 hours, then wait 5 hours while charging..no go!
I even thought about Mojo2 or Hugo 2, but many stated they dont have this "warmish" sound anymore like original Mojo - which I like about Mojo so i'm gonna try it as standalone DAC.

 

[onelivewire]

Following up on this thread, I just wired in this power supply feeding ~7.7V at the 7.5V setting. Currently testing to see if it resolves my intermittent shutoff issue mentioned above (I've been using a 5V USB power source with battery removed and the mojo shuts off intermittently mid-play in this setup - even when cooled to very reasonable temps via a USB fan).

Will report back on results. I do not currently have a diode in the circuit.

 

[onelivewire]

Coming up on 24 hours without a shutoff interrupt! This may have fixed my party-of-one issue.

 

[MohiJo]

Coming up on 24 hours without a shutoff interrupt! This may have fixed my party-of-one issue.

how did you connect it?

 

[onelivewire]

how did you connect it?

The adjustable power supply I linked above came with a screw terminal connection. Screwed in a male molex, tested the voltage from the wall and the battery to be sure they matched and just plugged her in! No soldering, even haha.

For now I simply have the wire flopping out the side of the case with the screws just barely threaded on that side. I wasn't ready to break out a dremel but may do so now that it seems to be working.

 

[vlach]

I've been using a 5V USB power source with battery removed and the mojo shuts off intermittently mid-play in this setup

I'm using a 5V USB external battery with battery removed and my Mojo never shuts off.

 

[onelivewire]

I'm using a 5V USB external battery with battery removed and my Mojo never shuts off.

Yeah, I've never found anyone else with this issue, but it really was obnoxious once I moved the mojo into our living room setup. Mid-movie or record and it would just cut out.

Fixing with a power supply felt like a long shot but I enjoy modding and for $20 it seemed worth it.

 

[MohiJo]

The adjustable power supply I linked above came with a screw terminal connection. Screwed in a male molex, tested the voltage from the wall and the battery to be sure they matched and just plugged her in! No soldering, even haha.

For now I simply have the wire flopping out the side of the case with the screws just barely threaded on that side. I wasn't ready to break out a dremel but may do so now that it seems to be working.

That's xactly what i am doing, only it is gonna be a thick DC cable ending in JST/molex plug. First it will have to use it slightly open because of the cable. Plan to let somebody drill the hole later.

 

[icnaiwhimor1975]

I heard in mojo 2 they removed the coupling capacitors on the headphone output - how to do the same in mojo 1?

 

[Kentajalli]

I heard in mojo 2 they removed the coupling capacitors on the headphone output - how to do the same in mojo 1?

You can not!
They replaced (not just removed) the said DC-Blocking capacitor with an active servo circuit.