Chord Mojo(1) DAC-amp ☆★►FAQ in 3rd post!◄★☆

[Pictograms]

Oh, you mean like this?

https://www.burosprinter.nl/luchtsp...MIzbjr5YbF4QIV7b_tCh27mQzSEAQYASABEgK_GfD_BwE

Exactly like that

 

[a-LeXx]

I presume that you are a fan of MQA.

Sorry, wrong. I‘m only talking about technical aspects. And I believe many fans of MQA would just share their excitement about how nice Mojo sounds with it.

And then skeptics like me would start asking wrong questions, like that one with filters

Whether there is actually any difference at all - that‘s another question. About as easy to answer as the question, whose religion is actually a proper one, and who was believing wrong things all the time

 

[miketlse]

Sorry, wrong. I‘m only talking about technical aspects. And I believe many fans of MQA would just share their excitement about how nice Mojo sounds with it. Whether there is actually any difference at all - that‘s another question. About as easy to answer as the question, whose religion is actually a proper one, and who was believing wrong things all the time

Here are the views of Rob Watts regarding MQA.
Why design a DAC to accurately reproduce music, then feed it with data generated by a lossy algorithm? GIGO.
Yes some people like MQA, but I don't think you will find many of them on the Chord threads.

 

[kumar402]

Sorry, wrong. I‘m only talking about technical aspects. And I believe many fans of MQA would just share their excitement about how nice Mojo sounds with it. Whether there is actually any difference at all - that‘s another question. About as easy to answer as the question, whose religion is actually a proper one, and who was believing wrong things all the time

This whole audiophile world works on hype isn't it? No point taking out Chord. Some website praise Schiit and some NOS. If you experience all you will realise they all have their strength and weaknesses

 

[a-LeXx]

Here are the views of Rob Watts regarding MQA.
Why design a DAC to accurately reproduce music, then feed it with data generated by a lossy algorithm? GIGO.
Yes some people like MQA, but I don't think you will find many of them on the Chord threads.

MQA has a possible range of implementations, and I believe that e.g. with MQA-CDs they are really screwing it up.

However, with the current tidal‘s implementation, that is, most content 48kHz and 24bit resolution, first, it‘s better than redbook already because of the resolution (not all 8 additional bits are used to carry the lossy signal), and secondly, adding the lossy unfolded information would at least not harm the main redbook-like part, but would require a much simpler filters with close to none impact already due to a fact that the cut-off frequency is now at 48kHz (assuming only one step of unfold to 96Ksps has been required/performed) compared to 22kHz with redbook content. And I‘m not a bat, I can‘t hear much of a difference even if they do screw the filter at 48kHz, while I‘ll certainly hear the difference if they do it at 22kHz It‘s as simple as this, from the technical point of view...

 

[GRUMPYOLDGUY]

Well, it‘s clear why they just CANNOT do MQA (not from the technical perspective).

If they do, and people would praise the sound quality, it would kill the major differentiator of the company - proprietary filtering.

Because for MQA, they cannot use their own filters, they have to do whatever MQA is telling to do - the same as competition does.

Absolute and utter nonsense. Fundamentally the output of MQA decoding is a stream of numbers at whatever rate the DAC supports. That one cannot implement a FIR filter just prior to that output stage is mind bogglingly idiotic. Consider DAPs that support MQA - one can still enable EQ in these cases which is nothing more than a FIR filter under the hood. The simple fact is MQA decoding is non trivial, and to do so in a hardware implementation is incredibly challenging. That, coupled with the notion that an end user is going to have a licensed copy of Vivado and $200 JTAG pod from Xilinx to update the firmware makes MQA on the Mojo pretty much impossible. That Chord are saying there is no increased fidelity in doing so is a) first of all, not incorrect nor b) surprising considering how quick they are to deflect when someone points out the limitations of their design.

Imagine, what would happen when the people would start to rave about how wonderful Mojo sounds with MQA? This would mean, those sophisticated filters were doing nothing, and the answer for the nice sound of Mojo is not in the overdone filtering, but in the simplistic amplifier design...

Oh come off it. These same people turn around and rave about their ridiculous cables and anti-vibe pads for their solid state devices. And yet nobody using those ridiculous things says the Mojo is incapable of producing pleasing sound.

If some people would start asking those technical questions with MQA support implemented, it would completely ruin the whole marketing strategy.

Their marketing strategy of "if it's well received it's because we're an amazing company and if people hate it it's because they're idiots" is already pretty bad.

That‘s why there will be never any MQA support with Mojo or devices with similar technical design, this would be, as is the designer acknowledges that his invention is actually doing nothing....

It would be possible with the latest multi-processor system-on-chip parts from Xilinx (i.e ZU9, etc) with PetaLinux running on the APU. Doing so doesn't mean the existing infrastructure is useless, it's just a lot of work to implement something that is objectively worse than uncompressed high fidelity source material.

 

[a-LeXx]

Absolute and utter nonsense. Fundamentally the output of MQA decoding is a stream of numbers at whatever rate the DAC supports. That one cannot implement a FIR filter just prior to that output stage is mind bogglingly idiotic. Consider DAPs that support MQA - one can still enable EQ in these cases which is nothing more than a FIR filter under the hood. The simple fact is MQA decoding is non trivial, and to do so in a hardware implementation is incredibly challenging. That, coupled with the notion that an end user is going to have a licensed copy of Vivado and $200 JTAG pod from Xilinx to update the firmware makes MQA on the Mojo pretty much impossible. That Chord are saying there is no increased fidelity in doing so is a) first of all, not incorrect nor b) surprising considering how quick they are to deflect when someone points out the limitations of their design.

Oh come off it. These same people turn around and rave about their ridiculous cables and anti-vibe pads for their solid state devices. And yet nobody using those ridiculous things says the Mojo is incapable of producing pleasing sound.

Their marketing strategy of "if it's well received it's because we're an amazing company and if people hate it it's because they're idiots" is already pretty bad.

It would be possible with the latest multi-processor system-on-chip parts from Xilinx (i.e ZU9, etc) with PetaLinux running on the APU. Doing so doesn't mean the existing infrastructure is useless, it's just a lot of work to implement something that is objectively worse than uncompressed high fidelity source material.

Sorry I quote everything, writing on an ipad and it‘s not very convenient to edit the text.

You got this wrong, I‘m talking here about company‘s philosophy, not about whether this is at all technically possible with Mojo.
And MQA renderer is actually nothing more than a DAC with a simple minimum phase slow roll-off filter (well, actually a number of similar filters).

That MQA allows only for a bit-perfect output - then I‘m with you, I also find it mumbo-jumbo, there is no actual technical reason for this limitation.
So, yes, MQA has some issues. But in case you don‘t need to EQ, e.g. MQA from Tidal is better resolution than a simple redbook content. It's all about streaming, it requires much less resources to stream quasi-redbook content compared to real high-res...

My point was, MQA collides with Chord‘s own mumbo-jumbo regarding their proprietary filtering. So it‘s either the way MQA dictates it, or the way Chord sees it. And of course Chord as a company would never allow to abandon their main differentiator and go for a competitor‘s (MQA) implementations - this would put the whole marketing strategy in danger.

What I‘m saying, is - there is a lot of mumbo-jumbo in this hobby and sometimes different philosophies collide and are completely and utterly incompatible, like in case of MQA and Chord.

This was also not at all intended as Mojo bashing, I‘m actually thinking about buying one...

 

[analogmusic]

This whole audiophile world works on hype isn't it? No point taking out Chord. Some website praise Schiit and some NOS. If you experience all you will realise they all have their strength and weaknesses

Kumar that is very Un-informed view that ignores basic sampling theory and the Maths behind it

The basic weakness of digital is transients...

And it seems to my ears that MQA does not address this fundamental problem. Even with a Native MQA Dac...

 

[a-LeXx]

And it seems to my ears...

That‘s a very true statement. Because there is no way to have a Chord product without their million-tap filter for a true double blind test. And comparing to other DACs is comparing apples to oranges... No doubt though that Chord’s products do generally sound good...

 

[Deftone]

Absolute and utter nonsense. Fundamentally the output of MQA decoding is a stream of numbers at whatever rate the DAC supports. That one cannot implement a FIR filter just prior to that output stage is mind bogglingly idiotic. Consider DAPs that support MQA - one can still enable EQ in these cases which is nothing more than a FIR filter under the hood. The simple fact is MQA decoding is non trivial, and to do so in a hardware implementation is incredibly challenging. That, coupled with the notion that an end user is going to have a licensed copy of Vivado and $200 JTAG pod from Xilinx to update the firmware makes MQA on the Mojo pretty much impossible. That Chord are saying there is no increased fidelity in doing so is a) first of all, not incorrect nor b) surprising considering how quick they are to deflect when someone points out the limitations of their design.



Oh come off it. These same people turn around and rave about their ridiculous cables and anti-vibe pads for their solid state devices. And yet nobody using those ridiculous things says the Mojo is incapable of producing pleasing sound.



Their marketing strategy of "if it's well received it's because we're an amazing company and if people hate it it's because they're idiots" is already pretty bad.



It would be possible with the latest multi-processor system-on-chip parts from Xilinx (i.e ZU9, etc) with PetaLinux running on the APU. Doing so doesn't mean the existing infrastructure is useless, it's just a lot of work to implement something that is objectively worse than uncompressed high fidelity source material.

He has returned.

 

[GRUMPYOLDGUY]

He has returned.

I'll be out of your hair soon enough. I'm quickly realizing why I left in the first place.

 

[cerspense]

Hey guys! I recently converted my Mojo into a desktop amp after the battery died!
https://imgur.com/a/RO32L0j
I used it as a desktop amp for about 2 years and the battery took a beating, as expected. It damn near exploded as there was a ton of pressure when I opened it up. Since I use it primarily as a deskop dac, I decided to convert it to be used without the battery entirely. I put in a power supply port on the side to provide a full 7.5V of power (the battery inside is 7.4V). If you don't need the full power and don't want to do any soldering, you can simply open it, remove the battery and power it just from USB, which is usually 5V. This setup has been amazing so far and is much better for my usage. If I ever need to bring it on a plane or something, it can still be powered over USB with a battery, it just won't perform as well with hard to drive headphones

 

[miketlse]

Hey guys! I recently converted my Mojo into a desktop amp after the battery died!
https://imgur.com/a/RO32L0j
I used it as a desktop amp for about 2 years and the battery took a beating, as expected. It damn near exploded as there was a ton of pressure when I opened it up. Since I use it primarily as a deskop dac, I decided to convert it to be used without the battery entirely. I put in a power supply port on the side to provide a full 7.5V of power (the battery inside is 7.4V). If you don't need the full power and don't want to do any soldering, you can simply open it, remove the battery and power it just from USB, which is usually 5V. This setup has been amazing so far and is much better for my usage. If I ever need to bring it on a plane or something, it can still be powered over USB with a battery, it just won't perform as well with hard to drive headphones

What do you think about this @Rob Watts ?

 

[Rob Watts]

I'll be out of your hair soon enough. I'm quickly realizing why I left in the first place.

I like grumpy old guys, as I fear I am consistently and steadily turning into one, in spite of my efforts not too!

What do you think about this @Rob Watts ?

Yes you can in practice run Mojo battery less, but it's not a qualified mode of operation. It's a good way to keep playing music until you get your battery replaced by your dealer. Do not under any circumstances add external PSUs though, this is potentially dangerous.

 

[435279]

Hey guys! I recently converted my Mojo into a desktop amp after the battery died!
https://imgur.com/a/RO32L0j
I used it as a desktop amp for about 2 years and the battery took a beating, as expected. It damn near exploded as there was a ton of pressure when I opened it up. Since I use it primarily as a deskop dac, I decided to convert it to be used without the battery entirely. I put in a power supply port on the side to provide a full 7.5V of power (the battery inside is 7.4V). If you don't need the full power and don't want to do any soldering, you can simply open it, remove the battery and power it just from USB, which is usually 5V. This setup has been amazing so far and is much better for my usage. If I ever need to bring it on a plane or something, it can still be powered over USB with a battery, it just won't perform as well with hard to drive headphones

I like it, at the price Chord charge for a replacement battery I can see somebody getting creative with a 3D printer and producing an external battery case. I would buy it.

If there is no charging of an internal battery I would imagine Mojo will run cooler too?