CHORD Mojo 2 Review (Portable DAC & HP Amp)

[staticV3]

In fact, I'm avoiding the USB input because a lot of people have experienced an issue where there's a sudden burst of full-volume white noise when using the USB input

That's a fault in USB bridges made by Cmedia. A brief interruption in the USB data connection will result in full-scale white noise being sent to the DAC.
Can be caused by dust/dirt in the USB jack, strain on the USB connectors, high levels of EMI, etc.

E1DA's early products were affected by this bug as well, but since Cmedia refused to provide a fix, all current E1DA products have switched to Comtrue bridges instead.

Hopefully, Watts has made the same decision with the Mojo 2
(anyone willing to check? )

 

[kanefsky]

That's a fault in USB bridges made by Cmedia. A brief interruption in the USB data connection will result in full-scale white noise being sent to the DAC.
Can be caused by dust/dirt in the USB jack, strain on the USB connectors, high levels of EMI, etc.

E1DA's early products were affected by this bug as well, but since Cmedia refused to provide a fix, all current E1DA products have switched to Comtrue bridges instead.

Hopefully, Watts has made the same decision with the Mojo 2
(anyone willing to check? )

I don't know what chips are used in the Mojo 2 but many people have experienced the white noise issue on the Mojo 2 and discussed it over on the head-fi forum. Some people are sure it's cable related but others insist that it happens when their player changes sample rates or when they don't set their player to use exclusive mode.

I haven't personally experienced it but I only used my Mojo 2 with USB briefly and now I'm only using it in setups that require optical or coax digital inputs. I have a bunch of other DACs for the USB use cases.

 

[staticV3]

Ah, I see. That's a shame.
It's an awful experience really, left me permanently paranoid while using the device on the go (it was fine on my desk, without any movement)

 

[SRKRAM]

That's a fault in USB bridges made by Cmedia. A brief interruption in the USB data connection will result in full-scale white noise being sent to the DAC.
Can be caused by dust/dirt in the USB jack, strain on the USB connectors, high levels of EMI, etc.

E1DA's early products were affected by this bug as well, but since Cmedia refused to provide a fix, all current E1DA products have switched to Comtrue bridges instead.

Hopefully, Watts has made the same decision with the Mojo 2
(anyone willing to check? )

Here's a photo of my mojo 2's pcba. No sign of anything from cmedia. I remember reading Rob Watts saying that the USB receiver is implemented in FPGA, but he didn't do that part. I also recall him writing that all chord products utilise the same USB implementation.
I've owned the mojo OG and 2 and have never experienced the white noise issue.
I like my mojos, but also like my DAPs for their all-in-one convenience when listening around the house. The mojo would replace my DAPs if poly were a bit better.

 

[50°F=Hellfire]

Why would I want this rather than a DAP with a screen and android operating system?

Because lots of DAPs have either
a) acoustic characteristics that are absolutely not acceptable in this day and age (i.E. more than 1 ohm output impedance, output power barely above that of a phone, a SINAD value that barely reaches the triple digits etc.) or
b) a maddeningly slow SoC (if I just play music on it, my DX160 runs noticeably hotter than my phone while running Genshin Impact at max settings).
If you find a DAP that neither of those things applies to, it'll probably cost something in the four-digit range.

 

[HansHolland]

1. higher latency (audio delay)
2. higher memory/CPU usage

It would be interesting to see how this one performs in terms of latency compared to some other DACs.

When comparing the reproduced music with live, then latency is an issue.
When enjoying music as a consumer, I don't care at all when the music starts (and ends) a very little bit later.

 

[Ler0ck]

Chord never make me disappointed.

 

[HansHolland]

Serious question, what is the technical difficulty in building such a sharp reconstruction filter?

Not much, it is technically very basic.

But, you have to do it yourself while most companies just use the reconstruction filters in the chip(set).

Thus it is the cost of the extra components and the cost of designing it (one time). Only a (little) cost. And when you think of it this way: why are not much more others doing it this way?

 

[staticV3]

Here's a photo of my mojo 2's pcba. No sign of anything from cmedia.

It might be on the other side of the pcb
Or maybe I'm wrong and the Mojo 2's USB bridge design just happens to have the same fault as bridges made by Cmedia. That'd be quite the coincidence

 

[Ra1zel]

In my point of view, absurdly expensive for what it does, design nightmare (micro USB in 2022), no Bluetooth, nothing special in performance.

Verdict: Vastly surpassed in usability and performance by something like khadas tea for 200$, use the rest to buy HD600 or moondrop variations if you want perfect harman target iem

 

[PeteL]

Ok, and what would be the cost in comparison to these incorrect slow filters?

I don't know, but in engineering, "cost" don't mean only monetary cost. it's the cost in processing ressources I was talking about in this case. It should also cost some latency as well. Some real estate as well. So this question is too complex to be answered. In this case, they where designing a product using a FPGA. There is also a development cost and BOM cost. If you are designing a general use IC chip it's going to be different considerations because they are also being used in products that need input to output synchronisation, so the latency becomes more of an important metric than if it's a pure DAC. It's always a cost vs benefits question. And it will vary on the design goal. It comes down to: is the audible benefit of having a technically perfect filter is worth more than the compromise you have to make to have it, that's the question Engineers have to answer before implementing it. In this case when we look at measurements, it looks like this objectively better filter did not significantly improve the typical rise of distortion at higher frequencies. Was it worth it? Maybe, maybe not.

 

[PeteL]

Yes, but a smartphone and a dongle?

Sure, I also find this product too bulky for me. I personally use Bluetooth, but the question was about DAP.

 

[thewas]

Why should it be a special achievement to get a good SNR with a battery powered device, isn't it rather opposite? (The reason why some "high end" amps had the option for battery operation). Surely, usually the voltage and power of the battery source is lower but for a DAC not very high values are needed, no?

Also it seems the battery is not replaceable, which is an absolute no-go for a $800 audio product, which in contrast to a smartphone can be used several decades. Thankfully the European Union is preparing an initiative against devices with not replaceable batteries.

 

[JJB70]

The thing about Chord and Watts is they can come out with some outrageous nonsense intended for the snake oil side of the hobby, yet they are also undeniably technically highly capable and good at what they do. Behind the asinine nonsense Watts can be guilty of the guy is very good at what he does. This performs way, way past audible thresholds in my opinion and I'd argue it is completely unnecessary, but, it isn't that expensive for a product from a high end boutique producer and unlike many companies in that segment at least you are getting something whoch offers outstanding (albeit inaudible) technical performance. Not my cup of tea but I can see the appeal, and Chord products genuinely have a very premium tactile quality.
My only caveat would be that I hope the battery issues associated with the original Mojo are in the past.

 

[3125b]

Am I misremembering, or did the first Mojo habe a rather terrible track record for reliability and repairability?

 

[MCH]

+Poly, reminds me a lot to my beloved Sony minidisc mz-r30. Similar form, size and weight. 1996

 

[JJB70]

Am I misremembering, or did the first Mojo habe a rather terrible track record for reliability and repairability?

They had an issue with batteries losing their charge a lot sooner than people expected, and the cost to replace them was ridiculous. As I remember it was a battery issue and the build quality and reliability of the rest of the unit was fine. However, given the importance of the battery that's a big issue.

 

[Phorize]

Truly futuristic performance coupled with some pretty mediocre industrial design, and where is the balanced output?

 

[kanefsky]

In my point of view, absurdly expensive for what it does, design nightmare (micro USB in 2022), no Bluetooth, nothing special in performance.

The Mojo 2 has USB-C in addition to micro USB. The micro USB connectors are there for backwards compatibility with the Poly streaming device which connects to them.

It's very common that as price and quality go up, the number of features goes down. That's why mono power amps often cost more than stereo power amps which often cost more than integrated amps which often cost more than AV receivers and so on.

I personally wouldn't want Bluetooth in the Mojo 2 since it would just add a lot of unnecessary complexity, potential for interference, etc. I use a Qudelix 5k or an iFi GO blu when I want Bluetooth. The size and weight of the Mojo 2 place it firmly into the wired DAC category for me.

 

[kanefsky]

They had an issue with batteries losing their charge a lot sooner than people expected, and the cost to replace them was ridiculous. As I remember it was a battery issue and the build quality and reliability of the rest of the unit was fine. However, given the importance of the battery that's a big issue.

One way they address that in the Mojo 2 is with "desktop mode", where it will run directly off of the dedicated USB power input and bypass the battery so that you can leave it connected and running for as long as you like without it constantly having to charge the battery. That also means that if the battery did fail you could at least still use it with an external USB power bank of your choice.