Review and Measurements of Chord Mojo DAC and Amp

[oufloued]

Technically it should:
- the charge pump circuit on Mojo classic, is sufficient for charging, no more. its output is not clean enough. It relies on the battery itself for final smoothing.
- remember that the DAC side of all Chord products is single ended.
- The battery can supply current surges when required by the headphones, the charge circuit can not.
- on Mojo2 the PSU is upgraded because of the above since it has a desktop mode.
This has been discussed to death on Headfi. Some users have reported that taking the battery out does no harm, they'd been diing it for some time!
Scientificly, I can not see how that is possible.

important UPDATE:
after a few months powering the mojo 1 with removed battery via the charging usb slot i must confirm Ken Tajalli's assumptions.
it took me quite a while to notice, but in the end it was obvious the sound quality degraded to a level where i could tell no difference to the headphone output of my smart phone. also the chassis got quite warm, even hot (i helped with cooling fins on chassis' top, but that was quite a fragile "solution".)
now i modded the mojo applying a budget 7,5 V with maximum 2000 mA power supply directly to the battery slot internally. i simply used the JST jack/cables of the old worn out battery. also i had to hone down the chassis on the headphones side a little to allow for the two cables leading out of the unit (that was the easiest solution to me, as i want to keep this precious modjo anyway - it sounds quite fine now to me. but i have to again burn in to it. let's see.

 

[Jimster480]

important UPDATE:
after a few months powering the mojo 1 with removed battery via the charging usb slot i must confirm Ken Tajalli's assumptions.
it took me quite a while to notice, but in the end it was obvious the sound quality degraded to a level where i could tell no difference to the headphone output of my smart phone. also the chassis got quite warm, even hot (i helped with cooling fins on chassis' top, but that was quite a fragile "solution".)
now i modded the mojo applying a budget 7,5 V with maximum 2000 mA power supply directly to the battery slot internally. i simply used the JST jack/cables of the old worn out battery. also i had to hone down the chassis on the headphones side a little to allow for the two cables leading out of the unit (that was the easiest solution to me, as i want to keep this precious modjo anyway - it sounds quite fine now to me. but i have to again burn in to it. let's see.

That is quite a bit of work! How come you didn't source a new battery?

 

[Ken Tajalli]

That is quite a bit of work! How come you didn't source a new battery?

I have one, he could have had it at cost.

 

[oufloued]

I have one, he could have had it at cost.

I don't use the mojo under way. While traveling (mostly train) I fall back to using bluetooth headphones: simplicity over audiophile quality of sound.
The mojo, I bought it 2 hand, sounds well enough in my modest main system.
In this situation, I find an ever dying battery to be not appropriate. Therefore the "mod" (no big deal at all, I'm amateur honer and solderer!).

The next step will be: powering the modjo with a laboratory linear adjustable power supply (which also could be the end of modjo - but: I'm curious how much voltage/current does it appreciate? The power light now is still green, had been blue with fully charged battery

 

[Ken Tajalli]

I don't use the mojo under way. While traveling (mostly train) I fall back to using bluetooth headphones: simplicity over audiophile quality of sound.
The mojo, I bought it 2 hand, sounds well enough in my modest main system.
In this situation, I find an ever dying battery to be not appropriate. Therefore the "mod" (no big deal at all, I'm amateur honer and solderer!).

The next step will be: powering the modjo with a laboratory linear adjustable power supply (which also could be the end of modjo - but: I'm curious how much voltage/current does it appreciate? The power light now is still green, had been blue with fully charged battery

Mojo prefers a decent SMPS. Linear PS is not good for Mojo, others have tried.
8V , 200mA is sufficient, so even a decent 2W one will do nicely.
Fit as big a cap inside, now that you have taken the battery out.
Get a 9V SMPS, use a diode on +Vcc to drop it to just over 8V.
That'll do.

 

[Deckard01]

Hello does it worth if can buy mojo 1 for 160 dollars or a dongle at this price range is better? Such as DC04 PRO or M1P that I was looking at as a budget and good option.

I care only for audio quality for Headphones such as HD600 and K701 and also mostly used with laptop.

Any suggestion would be really helpful!

Thanks for all

 

[Ken Tajalli]

Hello does it worth if can buy mojo 1 for 160 dollars or a dongle at this price range is better? Such as DC04 PRO or M1P that I was looking at as a budget and good option.

I care only for audio quality for Headphones such as HD600 and K701 and also mostly used with laptop.

Any suggestion would be really helpful!

Thanks for all

Mojo is better for sure.
Only issue with a used one is battery life.
Can easily be replaced.
$160 is a bit steep though.

 

[amanieux]

important UPDATE:
after a few months powering the mojo 1 with removed battery via the charging usb slot i must confirm Ken Tajalli's assumptions.
it took me quite a while to notice, but in the end it was obvious the sound quality degraded to a level where i could tell no difference to the headphone output of my smart phone. also the chassis got quite warm, even hot (i helped with cooling fins on chassis' top, but that was quite a fragile "solution".)
now i modded the mojo applying a budget 7,5 V with maximum 2000 mA power supply directly to the battery slot internally. i simply used the JST jack/cables of the old worn out battery. also i had to hone down the chassis on the headphones side a little to allow for the two cables leading out of the unit (that was the easiest solution to me, as i want to keep this precious modjo anyway - it sounds quite fine now to me. but i have to again burn in to it. let's see.

yes old hardware changing behavior when battery dies is a real problem, the 2009 macbook white i am writing on is cpu throttled down to 80% since my battery no longer hold charge, it seems it is a sofware decision in this case but the result is the same so we must pay attention to what performance we get when when buying old hardware, same thing with hifi amps with old capacitors, or vintage speakers with loosened driver membrane i am pretty sure they don't perform/measure like they did when they were new

 

[Ken Tajalli]

decent batteries for Mojo classic are readily available on Aliexpress for $20 or so.
I see no reason to use an external PSU, risk RFI and ground loop or whatyouknow.
Unless one is having fun.
I am one of those myself.

 

[amanieux]

today we can find used mojo 1 for $250, is it still competetive in today's market at this price ? any suggestion for something 90% as good for less money (for iem exclusively ) ? thanks

 

[Blashyrkh]

today we can find used mojo 1 for $250, is it still competetive in today's market at this price ? any suggestion for something 90% as good for less money (for iem exclusively ) ? thanks

I am currently selling this for 200euros in italy, and there's no much market...I should try internationally

If the battery is still good (mine lasts 6hours after probably 7 years) I think is a decent price

 

[Jimster480]

today we can find used mojo 1 for $250, is it still competetive in today's market at this price ? any suggestion for something 90% as good for less money (for iem exclusively ) ? thanks

Just use a FiiO KA13 dongle. It is like $79 and offers great performance.

 

[Ken Tajalli]

today we can find used mojo 1 for $250, is it still competetive in today's market at this price ? any suggestion for something 90% as good for less money (for iem exclusively ) ? thanks

Depends on your intended use.
The original Mojo is very capable and replacement batteries are available from Aliexpress.
A dongle has been suggested, a good one. If you do a little research, there are even better dongles about.
But does a dongle do for you?
- Dongles get their power from the host USB. So if you want to use your mobile phone with it, it will drain your battery fast! they use from 150mA to +300mA, that is a big drain on a phone's battery, but a with a laptop, no problems.
- A DAC/AMP with rechargeable own battery is better for portable use, but it is bulkier and heavier.
- What headphones? Mojo can just about drive anything, most dongles would struggle with low-impedance loads, due to their high output impedance.
If you are looking for something like a Mojo, then get one, you won't go wrong!
But if a dongle can do the job for you, go for the ifi or some others, with good measurements available here on ASR.

 

[Jorj]

I would think $250 is not a good value. I have been using the $129 E1DA 9038D6K and it is a much better value, plus does not require charging. I keep my old Mojo around for comparisons and such, but it does not get much play these days.

 

[Jimster480]

Depends on your intended use.
The original Mojo is very capable and replacement batteries are available from Aliexpress.
A dongle has been suggested, a good one. If you do a little research, there are even better dongles about.
But does a dongle do for you?
- Dongles get their power from the host USB. So if you want to use your mobile phone with it, it will drain your battery fast! they use from 150mA to +300mA, that is a big drain on a phone's battery, but a with a laptop, no problems.
- A DAC/AMP with rechargeable own battery is better for portable use, but it is bulkier and heavier.
- What headphones? Mojo can just about drive anything, most dongles would struggle with low-impedance loads, due to their high output impedance.
If you are looking for something like a Mojo, then get one, you won't go wrong!
But if a dongle can do the job for you, go for the ifi or some others, with good measurements available here on ASR.

The one I suggested has a low (0) output impedance and can deliver upto 550mw in desktop mode. 170mw in non-desktop mode.
SINAD as done by their own testing is 109+.
Power draw from my Xperia isn't too bad, I would say around 10% per hour draw in normal mode.

 

[Marss72]

I know i'm in not in the right forum with my comment(s) but i do wanna share my thoughts and i have a question about the Mojo 1.
At first i want to say that i also don't like how the Mojo looks and how it works but for me in my setup it's the best sounding dac i've had/heard.
It sounds dynamic, detailed enough, on the warm side of neutral while still sounding crisp/detailed (not harsh) in the higher regions. With some dacs i missed that 'sparkle/(micro)detail' in the highs. Some other dacs íve had on the other hand sounded too thin, airy, neutral, analytical or dry. Maybe the soundstage of the Mojo 1 could be wider but overall this is the dac i like the most so far (at least in this (budget) price range).

I bought mine secondhand and it's a modified one (permanent powersupply) for little money (no regrets). Only thing i find irritating is that it will shutdown by itself after a few minutes of inactivity/no signal. This means i will have to turn it on each time manually unless there is a constant signal (playing music or watching tv all the time).

Now i wander if there is a way to bypass this or to let the Mojo stay on constantly (unless i turn it off myself)?

 

[ahofer]

@Marss72 sometimes there is a button sequence/cheat code that can change the setting. I'd inquire with Chord.

I won't argue your subjective conclusions, but I do believe most or all of the Chord DACs have higher output than average, which will tend to advantage them in non level-matched comparisons, since louder sounds better and makes high and low details more audible (Fletcher-Munson). The Mojo output, per Google, is over 3 volts.

 

[VientoB]

I've been using a Mojo in my system since 2018. When I switched to an SMSL M300SE I honestly thought they sounded so similar. In fact I think I subjectively preferred the M300SE.

 

[Galliardist]

@Marss72 sometimes there is a button sequence/cheat code that can change the setting. I'd inquire with Chord.

I won't argue your subjective conclusions, but I do believe most or all of the Chord DACs have higher output than average, which will tend to advantage them in non level-matched comparisons, since louder sounds better and makes high and low details more audible (Fletcher-Munson). The Mojo output, per Google, is over 3 volts.

The power problem will be due to that permanent power supply modification being a botch job. No point in talking to Chord about that.

By default, the Mojo will switch the 3v setting out when it loses power completely. As a result, unless @Marss72 is switching it back in every time, or the modification is somehow defaulting, output will be 2v in this case and the volume control will be active. The auto shutdown is only supposed to happen when running with no power plugged in according to the past and present Mojo owners I know. Either the battery is not being sufficiently charged (possibly needs replacing) or it is out of circuit as part of the fix but the power supply mod leaves the Mojo thinking it is only on battery.

I'd suggest the "added sparkle" if present in the sound waves is distortion, and the likely cause is that permanent power supply modification.

I'd also suggest that the power supply modification is faulty, and personally I'd take it out of service now and get it checked by someone competent, before something worse happens. Maybe look for a cheap unmodified one to replace it?