Review and Measurements of Chord Mojo DAC and Amp

[Veri]

Not aware of that. I guess that something was wrong in Amir’s test setup that day.

There could easily have been some revisions over the year, though. Not abnormal.

 

[SRKRAM]

I bought a new mojo in late 2020 and the PCB revision is from 22/03/2017 as can be seen from the photo attached. Not sure if there have been any later revisions. This one picked up less noise from my mobile than the first mojo which I bought, but I recon that's due to 2G mobile not being used any more.

BTW, I just bought a mojo 2 as well.

 

[raif71]

I bought a new mojo in late 2020 and the PCB revision is from 22/03/2017 as can be seen from the photo attached. Not sure if there have been any later revisions. This one picked up less noise from my mobile than the first mojo which I bought, but I recon that's due to 2G mobile not being used any more.

BTW, I just bought a mojo 2 as well.
View attachment 183665

How does the Mojo 2 sound like? I have the 1st mojo and like it very much.

 

[SRKRAM]

How does the Mojo 2 sound like? I have the 1st mojo and like it very much.

If yo like the OG mojo, you might not actually like the mojo 2. The OG has a good level of detail, but sounded quite intimate and natural to me. The mojo 2 sounds brighter and harder - I thought I liked 'transparent' sound, but not like this. I'll give it a bit of time though. At the moment it sounds better with my Denon D9200s than with my 2021 LCD-Xs, whereas I liked the OG with both. I don't find the EQ controls very useful for my use. The bass shelf starts too high for my liking, and I don't see any way to EQ 4K which is what I need for the LCD-X. The micro usb ports and USB-C port which looks like it was stuck on afterwards (it's a plastic bump) are also a bit of a let down.

 

[raif71]

If yo like the OG mojo, you might not actually like the mojo 2. The OG has a good level of detail, but sounded quite intimate and natural to me. The mojo 2 sounds brighter and harder - I thought I liked 'transparent' sound, but not like this. I'll give it a bit of time though. At the moment it sounds better with my Denon D9200s than with my 2021 LCD-Xs, whereas I liked the OG with both. I don't find the EQ controls very useful for my use. The bass shelf starts too high for my liking, and I don't see any way to EQ 4K which is what I need for the LCD-X. The micro usb ports and USB-C port which looks like it was stuck on afterwards (it's a plastic bump) are also a bit of a let down.

Of all my dac/amp... I think the mojo has the better sound with my iems (moondrop blessing 2 and tin hifi p2). I am comparing it to the ifi hipdac and topping dsd nx4. Only the sony pha-2 and pha-3 in my opinion is on par with the mojo. I'm quite disappointed to hear that mojo2 hasn't the same sound as the 1st, as the mojo that I have now is getting old. I dread hearing the brighter and harder (harsher?) of the mojo 2 as this is what it sounds like with the nx4.

 

[SRKRAM]

I bought a new mojo in late 2020 and the PCB revision is from 22/03/2017 as can be seen from the photo attached. Not sure if there have been any later revisions. This one picked up less noise from my mobile than the first mojo which I bought, but I recon that's due to 2G mobile not being used any more.

BTW, I just bought a mojo 2 as well.
View attachment 183665

Here's the mojo 2 if interested (I just blanked out a couple of marks which I thought could be used for identification):

 

[Veri]

Here's the mojo 2 if interested (I just blanked out a couple of marks which I thought could be used for identification):
View attachment 183862
View attachment 183863

Seems like most actual changes will be in firmware, code/programming.. wouldn't be surprised if it measures hardly different from Mojo 1.

 

[snaans]

Is there a practical/engineering reason why neither of the Mojos have analog input? I bought the first Mojo preowned last year, and find it kind of absurd for the Mojo 2 to have four different digital inputs, but no way to simply amplify an analog signal.

Sorry if this is obvious, I googled a bit but the Head-Fi thread seemed to be dismissive of the idea.

 

[dc655321]

Is there a practical/engineering reason why neither of the Mojos have analog input? I bought the first Mojo preowned last year, and find it kind of absurd for the Mojo 2 to have four different digital inputs, but no way to simply amplify an analog signal.

Sorry if this is obvious, I googled a bit but the Head-Fi thread seemed to be dismissive of the idea.

It’s a DAC. Only.

 

[snaans]

It’s a DAC. Only.

But this isn't really true, is it? It is capable of driving headphones just fine. I can't see a real reason *not* to include an analog input, it limits the functionality of the device in certain usecases (for example, I use Korg DS-10 as a synth on my old DS, and would love to be able to amplify the headphone jack with my Mojo, since the max volume on my HD 650s is pretty quiet). Would bypassing the DAC chip and running an analog signal straight to the amplifier not be feasible?

 

[dc655321]

But this isn't really true, is it?

It is.

 

[maverickronin]

Would bypassing the DAC chip and running an analog signal straight to the amplifier not be feasible?

It's perfectly feasible, especially if they keep it straight analog and bypass the crossfeed which is probaly done in DSP. It's just that Chord's schtick is its overly complicated DAC filters and letting something else do the conversion both steals it thunder and is a minority use case which they aren't interested in catering to.

 

[Music1969]

Silly question regarding @Archimago 's recent Chord Mojo measurement. cc @mansr

This plot below shows 44.1k input test signal but 100dB attenuation number is determined at 24kHz point, which is applicable to 48kHz input signal?

Why not look at attenuation to 'Nyquist' at 22kHz but 44.1kHz input, which is also shown on the plot

 

[pkane]

Silly question regarding @Archimago 's recent Chord Mojo measurement. cc @mansr

This plot below shows 44.1k input test signal but 100dB attenuation number is determined at 24kHz point, which is applicable to 48kHz input signal?

Why not look at attenuation to 'Nyquist' at 22kHz but 44.1kHz input, which is also shown on the plot

100dB at 22,400 not at 24k. It’s just the shape of the chosen filter, Arch is showing that it doesn’t attenuate as much at Nyquist, thus is a bit leaky.

 

[Music1969]

100dB at 22,400 not at 24k.

Sorry my mistake mentioning 24k.

But same question. 22.4k isn't Nyquist.

Isn't that what we're interested in, regarding attenuation? The amount of attenuation by the Nyquist freq?

 

[pkane]

Sorry my mistake mentioning 24k.

But same question. 22.4k isn't Nyquist.

Isn't that what we're interested in, regarding attenuation? The amount of attenuation by the Nyquist freq?

Sufficient attenuation before Nyquist is what’s theoretically needed. Chord filter is placed so that it doesn’t reach full attenuation until past Nyquist. So it’s a little leaky, but that’s unlikely to cause any audible problems since it’s sharp enough and has some decent attenuation by 22.05k.

What’s your concern?

 

[Music1969]

Sufficient attenuation before Nyquist is what’s theoretically needed. Chord filter is placed so that it doesn’t reach full attenuation until past Nyquist. So it’s a little leaky, but that’s unlikely to cause any audible problems since it’s sharp enough and has some decent attenuation by 22.05k.

What’s your concern?

No concern, just trying to understand why the attenuation number is given past the Nyquist point.

I thought it made more sense to specify the amount of attenuation before Nyquist.

More just trying to understand than a concern.

At least your comment that Mojo filter is a bit leaky tells me my thinking (not concern) is on the right track.

I'm not coming from an audibility angle either. Probably inaudible as you hinted.

 

[pkane]

No concern, just trying to understand why the attenuation number is given past the Nyquist point.

I thought it made more sense to specify the amount of attenuation before Nyquist.

More just trying to understand than a concern.

At least your comment that Mojo filter is a bit leaky tells me my thinking (not concern) is on the right track.

I'm not coming from an audibility angle either. Probably inaudible as you hinted.

As long as the listener isn’t concerned with hearing down to -200dB, that filter should be good enough

 

[Music1969]

As long as the listener isn’t concerned with hearing down to -200dB, that filter should be good enough

-200dB is not enough ! See:

Watts Up...?

I‘m glad I was able to introduce you to new music that you liked, Christer. I know you set high standards for what you listen to. The funny thing is I did not realise the first video I posted was mono. My music system at the time was disassembled into its component parts and my first listen...

www.head-fi.org

 

[mansr]

No concern, just trying to understand why the attenuation number is given past the Nyquist point.

He is simply describing the shape of the filter, and it happens to reach its full attenuation at that frequency.