CHORD Mojo 2 Review (Portable DAC & HP Amp)

[Madlop26]

If you only care about the most features for the lowest price, then the Mojo 2 isn't the best choice regardless of category. But lots of people are willing to pay for premium quality and would rather buy an Audi than a Hyundai (or whatever example you'd like to pick) even if it doesn't go any faster or have more features.

There's also a whole continuum between "portable" and "desktop." The Mojo 2 is a great size to go along with a laptop like a MacBook Air or a full-size iPad when you're sitting on the couch, for example.

Having owned a Hyundai and an Audi I would admit the "premium" factor is there, but reasonable priced?, that depends on you, but in this case hmm.. i do not see any premium . there are so many good alternatives out there, with reasonable prices.

 

[dc655321]

I don‘t know what exactly the internal change was but Rob told me the highs were closer to the Hugo 2 than the original Mojo, which could be a bit sharp up top. To me it’s the biggest audible change. Cymbals and strings just sound much airier than my Mojo 1…

You looked at the measurements back on page one, right? There is nothing in them to suggest other than neutral passband behavior.

I guess your observation was made with no controls in place?

 

[staticV3]

To me it’s the biggest audible change. Cymbals and strings just sound much airier than my Mojo 1…

Was your comparison done blind, with matched levels? If so, what's your confidence score of picking out the right Mojo?

If your impressions were instead done sighted, with no controls in place, then please have a look at this guide that Amir made about how to do proper comparisons between audio gear.

 

[Ken Tajalli]

Was your comparison done blind, with matched levels? If so, what's your confidence score of picking out the right Mojo?

If your impressions were instead done sighted, with no controls in place, then please have a look at this guide that Amir made about how to do proper comparisons between audio gear.

Do you guys even know who Dan Clark is?
He knows how to do a listening test, don't assume.

Dan Clark Audio - Official HomePage

danclarkaudio.com

 

[Ken Tajalli]

From a 7.4V battery and using low drop output opamps you could get about 7Vpp = 1.9Vrms.
To charge such a battery from 5V already requires a DCDC converter.

I say potato , you say potayto! . . . charge-pump, DCDC converter, SMPS ......

Seeing that the output voltage swing is about 5.2V in higher imp. (14.7Vpp) there would have to be about 15V inside.
For the output to be in real class-A for 300ohm HP's a 25mA idle current would be needed = 0.4W per channel in wasted heat. (1W including a good converter for audio alone).

I believe the original Mojo dissipated 1.5W playing and over 3W charging and playing - so that thick case was always counter-productive.
I went to lengths to get the heat out, using shaped copper plates and heat transfer pads!
I did it to save the battery from heat, mine lasted a good few years - a $20 replacement from AliExpress (anything but express!) lasted a year or so while I still had it, I assume still going. (flogged on eBay)

 

[staticV3]

He knows how to do a listening test, don't assume.

I don't assume. That's why I asked.

 

[SRKRAM]

Was your comparison done blind, with matched levels? If so, what's your confidence score of picking out the right Mojo?

If your impressions were instead done sighted, with no controls in place, then please have a look at this guide that Amir made about how to do proper comparisons between audio gear.

As I mentioned, I found the treble of the mojo 2 quite jarring when I first heard it. It's sharper than the mojo OG, and I didn't like it at first. They would be quite easy to tell apart.

 

[solderdude]

I went to lengths to get the heat out, using shaped copper plates and heat transfer pads!
I did it to save the battery from heat, mine lasted a good few years

Yes, heat and batteries don't go well together.
I wonder why Rob did not use a lower idle current, if that is indeed where a big chunk of the heat came from. Probably so he could lure class-A believers ?
Most likely the processing at a high speed (for the kazillion tap filters) also produces some heat.

Mojo 2 equally warm ?

 

[srkbear]

There's something weird going on here. I assumed that the switch to USB-C on the iPad meant that the port would work like a normal USB port, so why would a USB-C CCK exist? If it is required, how can some DACs work with a simple USB-C cable?

I think it has something to do with the amount of power the attached device draws from the port, and whether the device’s output is configured as a compatible OTG port.

I have a 2019-2020 model iPad Pro, and several portable DACs with USB C or USB A connectors. With my iFi Gryphon, which comes with Apple-compatible OTG lightning and USB C cables, it works fine with no CCK. With my older micro iDSD BL, I have to use the CCK with the iPad and have to plug in the charging port on it to power the iPad during use or I get a compatibility error (basically one stating that the device exceeds the power handling of the iPad). The CCK is also nice to allow the iPad to be charging while the DAC is in use, and of course I need it for the DACs I have that have USB A connectors (such as the Dragonfly).

For later iPad Pros (such as the 2021 model), I think they employed a more powerful USB bus that can handle high power devices like external hard drives and external amps. But I know for sure that the early iPads, even those with USB C ports, were not configured to allow bypass of the internal DAC without the CCK.

 

[Ken Tajalli]

Yes, heat and batteries don't go well together.
I wonder why Rob did not use a lower idle current, if that is indeed where a big chunk of the heat came from.

He did, that's why it is class A at higher impedances, for lower impedances it reverts to class AB.
Half the heat is from the FPGA and the USB input chip, and while charging, the DCDC converter circuitry plus battery charging etc.

Probably so he could lure class-A believers ?

No, couldn't care less I believe.

Most likely the processing at a high speed (for the kazillion tap filters) also produces some heat.

about 50K taps I believe, DSP and volume control is also done at very high oversampling mode.

Mojo 2 equally warm ?

Almost, a little less.

 

[staticV3]

As I mentioned, I found the treble of the mojo 2 quite jarring when I first heard it. It's sharper than the mojo OG, and I didn't like it at first. They would be quite easy to tell apart.

Thanks for your impressions, but I was asking Dan Clark.

 

[kanefsky]

Mojo 2 equally warm ?

One big difference with the Mojo 2 is the "Intelligent Desktop Mode", where it will bypass the battery and run directly from the charger power once the battery is charged. The main benefit is that it greatly extends the life of the battery but I imagine it affects heat as well. I leave mine connected to a charger 24/7 and it doesn't get warm at all. I suppose if you run it off battery for a long time and then plug it in to recharge while continuing to play it would get warm until the battery is charged but I never use it like that so I can't say.

 

[solderdude]

No, couldn't care less I believe.

Then he could have saved battery power and heat build up.
It was either to reel in class-A believers or poor engineering of the HP amp section which is hard to believe.
There is no need to have a high idle current.

 

[kanefsky]

I think it has something to do with the amount of power the attached device draws from the port, and whether the device’s output is configured as a compatible OTG port.

Yeah that's exactly what I said about the power. Since the Mojo 2 has a battery and a separate power plug it doesn't need to draw any power from the iPad so it works fine. For devices that do need significant power, you don't need a special CCK (which doesn't exist for USB-C anyway), but you can just use any USB hub that supplies power (although I would personally try to avoid any solution that required extra dongles, cables, hubs, etc. for regular use).

 

[Dan Clark]

Was your comparison done blind, with matched levels? If so, what's your confidence score of picking out the right Mojo?

If your impressions were instead done sighted, with no controls in place, then please have a look at this guide that Amir made about how to do proper comparisons between audio gear.

You looked at the measurements back on page one, right? There is nothing in them to suggest other than neutral passband behavior.

I guess your observation was made with no controls in place?

Amir's work showed there are certainly enough measurable improvements in the product to support a claim of audible improvements, and as I use Chord gear 6 hours a day supporting my product design and listening tests this product was an improvement to me.

It was 100% sighted, totally lacking in any controls, without level matching, performed by a totally fallible human of questionable intelligence, perhaps without adequate caffeine, possibly too much Scotch, in a neighborhood with high ambient noise, using music of questionable artistic merit, and overall a genuine shitshow of a methodology. If you insist on that sort of "science" overhead to support every single comment and don't believe someone might actually hear some of the differences that were measured and be able to articulate their effect in a simple way, then you should ignore me and move on.

 

[solderdude]

One big difference with the Mojo 2 is the "Intelligent Desktop Mode", where it will bypass the battery and run directly from the charger power once the battery is charged. The main benefit is that it greatly extends the life of the battery but I imagine it affects heat as well. I leave mine connected to a charger 24/7 and it doesn't get warm at all. I suppose if you run it off battery for a long time and then plug it in to recharge while continuing to play it would get warm until the battery is charged but I never use it like that so I can't say.

To extend battery life of a Lithium battery (when not in use, say always in desktop mode) would be to not fully charge the battery but stop charging at 70% capacity.
Low heat also helps. Good to hear it does not get as warm.

 

[srkbear]

You appear to be mistaken, but it would be interesting to know what you are referring to.

I promise—I am not the kind of person to keep doubling down if I’m mistaken. This is the equivalent of the Lightning CCK for the iPad. Like the iPhone version, it has come in two hardware versions, and the earlier models are no longer compatible with later model iPhones and iPads. This AV adapter is required for earlier generation iPads and iPad pros with USB-C ports to provide adequate power for power hungry devices attached, and they also allow bypass of the internal DAC on early iPad models plus compatibility for DACs that use USB A connectors.

There are also firmware updates for these devices that are automatically updated upon connection, and unlike other iOS peripherals, you get a popup window for the upgrade process as its installing.

Again, the most recent model iPad Pros have a much more powerful USB bus, and I don’t own one. But for my 2019-2020 model, at least two of my portable DACs will not work without this adapter.

 

[solderdude]

It was 100% sighted, totally lacking in any controls, without level matching, performed by a totally fallible human of questionable intelligence, perhaps without adequate caffeine, possibly too much Scotch, in a neighborhood with high ambient noise, using music of questionable artistic merit, and overall a genuine shitshow of a methodology. If you insist on that sort of "science" overhead to support every single comment and don't believe someone might actually hear some of the differences that were measured and be able to articulate their effect in a simple way, then you should ignore me and move on.

At least you have access to a good headphone during the testing...

 

[SRKRAM]

Thanks for your impressions, but I was asking Dan Clark.

Sorry to have wasted your time.

 

[srkbear]

Yeah that's exactly what I said about the power. Since the Mojo 2 has a battery and a separate power plug it doesn't need to draw any power from the iPad so it works fine. For devices that do need significant power, you don't need a special CCK (which doesn't exist for USB-C anyway), but you can just use any USB hub that supplies power (although I would personally try to avoid any solution that required extra dongles, cables, hubs, etc. for regular use).

This may be true for later model iPads (we are starting to agree here which makes me happy!), but even with powered DAC/amps, I have a couple of portables that require me to use the kit I posted and have it connected to power for them to work on my second gen iPad Pro. I get a compatibility error (even with the latest firmware), and the iPad refuses to switch the audio output to the external DAC without it. I cannot explain why, and these are also four or five year old DAC/amps. I’m guessing newer DACs are starting to use more compatible USB ports themselves, similar to the inclusion of lightning OTG cables that obviate the use of the older iPhone CCKs. All of the portables I’ve purchased in the last couple of years (both from iFi and FiiO) come with lightning and USB C OTG cables that circumvent the use of any other adapters.

The only reason I raised any concern to the OP is that I don’t know what generation iPad he has, and since I don’t own any Chord products I don’t know how proactive they are with Apple compatibility. But as you said, the Mojo 2 is working for you, so I edited my original post to correct that yesterday.