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

[Mython]

   

Spoiler: Warning: Spoiler!

well looking at Dave, Dave got 3 things which are better

- Better noise shaper (350 DB) compared to 200 DB in Mojo, Hugo and TT
- More taps (168,000 vs 26,000 in Hugo and Mojo)
- 2nd order noise shaper analog stage.

Unless there is some magical FPGA that gives Dave Spartan 6 LX75 capability in the size and price of the Artix 7 (which isn't going to happen in 2017), I see  0 % chance of a Mojo update.

Actually, Chord does not publish or say how many taps are in the Mojo. I think because it's implemented in a different way than their other products.

 
 
Chord were reticent to discuss it, in the early months, after release, but eventually relented:
 

  Regarding Mojos number of taps vs Hugo, they're allocated and run differently, but the end result is equivalent performance, and in fact, part of Mojos code is newer than that in Hugo, allowing the WTA filter to run at an eye-watering 768 kHz, if you had such files and a transport capable of feeding them to Mojo! (totally unnecessary, at this point in time, but the capability is there). The point is that Mojo is a very potent DAC and it would be incorrect to assume it is only has a fraction of Hugos capability.
 
 
 

Spoiler: From post #3

Quote:

  Just to correct things - it is a 15T that is used on the Mojo.
 
That has 16,640 logic cells and 45 dsp cores. 44 cores are used in Mojo.
 
The overriding design decisions were about power consumption, so although more DSP cores are used than Hugo, that's to reduce power, as the DSP cores are run at a much lower clock speed. To give you another example of lower power, with Hugo when I needed a bigger multiplier I used one DSP core with FPGA fabric (logic cells) added to create the larger multiplier. With Mojo, to save power, I used multiple DSP cores and no fabric to create larger multipliers.
 
Only the WTA filter is different, the rest of the audio path has Hugo code.
 
Rob

 
 

 

26,000 taps is the closest to a definitive statement as I've read ... the same as I've seen specified for Hugo.

I'm sure it's called out earlier in the thread, just going from memory as I'm far too lazy to search for it!

Actually it's about twice as many as Hugo but run at half the speed giving approximately the same number crunching power in terms of DSP ..... We have mentioned this before, but didn't want to put much focus on it as this is a small only part of the over design of Rob's overall topology

 
 

it was always our intention to try to match the performance of Hugo To do this without using as much power as Hugo. Therefore Rob used more DSP cores but run differently to match the performance of Hugo but at far lower power demands. JF

 

 

[Takeanidea]

Anyone interested in any other DAC than the Mojo with their Christmas monies needs to have a good old listen to the Chord at great length before they put their money into something else in a similar price range. If sound quality is the prime motivator then I'm not hearing any real competitors despite over a year available to R&D a winner

 

[gonzfi]

I don't think anyone buying Mojo in the next few days will be disappointed about what's announced at CES, in 8 days time.

Sounds interesting....

 

[Mython]

 

I don't think anyone buying Mojo in the next few days will be disappointed about what's announced at CES, in 8 days time.

Sounds interesting....

 
It's so easy to interpret textual communication in multitudinous ways - just to be clear: when I said 'in the next few days', I meant including the days before CES.
 
It's no secret that Chord intend to look after their Mojo customers.

 

[UNOE]

Be careful with ferrite cores. They can reduce dynamics in the audio, in my experience. 

That's should be only when you use it on a anolog cable like RCA's. Signal will not change on a USB cable or power only cable (obvious cause no signal).

 

[Mediahound]

That's should be only when you use it on a anolog cable like RCA's. Signal will not change on a USB cable or power only cable (obvious cause no signal).

That's a common misconception. The USB cable is transmitting digital information via analog electrical signals.

More here: http://www.digitalaudioreview.net/2015/09/curious-for-the-curious-a-knockout-usb-cable-from-australia/

 

[rkt31]

That's a common misconception. The USB cable is transmitting digital information via analog electrical signals.

More here: http://www.digitalaudioreview.net/2015/09/curious-for-the-curious-a-knockout-usb-cable-from-australia/

that's true that even digital signals are carried in analog electrical signals. ferrite core only remove noise part not that it removes or change the electrical signal which carry digital bits, if that was the case there would have been clicks and pops caused by the missing digital information which i  have not experienced even when using upto three small cores on a short coaxial and usb cable. initially i felt there were some lack of dynamics using jitterbug along with ferrite cores but call it brain burn in or some unexplained phenomena, i never feel anything missing or lacking in dynamics after continuous use. may be there is some continuous cable burn in/ adjustment in crystal structure as you change the noise pattern of signal by using these tweaks like jitterbug and/or ferrite cores. the effect of jitterbug along with few ferrite cores is enormous . it is as if the last bit of noise is sucked out of the music and there is just pure music left.

 

[Deftone]

Actually, Chord does not publish or say how many taps are in the Mojo. I think because it's implemented in a different way than their other products.

Mojo has 52,000 taps at half speed

 

[Dithyrambes]

Get a trigger to get the mojo unlocked as desktop dac with 52k taps...because battery issue is nonexistent.....then revert back to 26k on the go. Sounds promising to me kkk

 

[UNOE]

 

That's should be only when you use it on a anolog cable like RCA's. Signal will not change on a USB cable or power only cable (obvious cause no signal).

That's a common misconception. The USB cable is transmitting digital information via analog electrical signals.

More here: http://www.digitalaudioreview.net/2015/09/curious-for-the-curious-a-knockout-usb-cable-from-australia/

okay fair enough...  but that should not change dynamics before it even hits a DAC though, right?

 

[x RELIC x]

okay fair enough...  but that should not change dynamics before it even hits a DAC though, right?

According to Rob it does, specifically outlined here:

http://www.head-fi.org/t/784602/chord-mojo-dac-amp-faq-in-3rd-post/3495#post_12044746

Spoiler: Warning: Spoiler!

Just to clarify:

1. SPDIF decoding is all digital within the FPGA. The FPGA uses a digital phase lock loop (DPLL) and a tiny buffer. This re-clocks the data and eliminates the incoming jitter from the source. This system took 6 years to perfect, and means that the sound quality defects from source jitter is eliminated. How do I know that? Measurements - 2 uS of jitter has no affect whatsoever on measurements (and I can resolve noise floor at -180dB with my APX555) and sound quality tests against RAM buffer systems revealed no significant difference. You can (almost) use a piece of damp string and the source jitter will be eliminated.

2. USB is isochronous asynchronous. This means that the FPGA supplies the timing to the source, and incoming USB data is re clocked from the low jitter master clock. So again source jitter is eliminated.

So does this mean that any digital cable will do?

Sadly no. Mojo is a DAC, that means its an analogue component, and all analogue components are sensitive to RF noise and signal correlated in-band noise, so the RF character of the electrical cables can have an influence. What happens is random RF noise gets into the analogue electronics, creating intermodulation distortion with the wanted audio signal. The result of this is noise floor modulation. Now the brain is incredibly sensitive to noise floor modulation, and perceives this has a hardness to the sound - easily confused as better detail resolution as it sounds brighter. Reduce RF noise, and it will sound darker and smoother. The second source is distorted in band noise, and this mixes with the wanted signal (crosstalk source) and subtly alters the levels of small signals - this in turn degrades the perception of sound stage depth. This is another source of error for which the brain is astonishingly sensitive too. The distorted in band noise comes from the DAP, phone or PC internal electronics processing the digital data, with the maximum noise coming as the signal crosses through zero - all digital data going from all zeroes to all ones. Fortunately mobile electronics are power frugal and create less RF and signal correlated noise than PC's. Note that optical connection does not have any of these problems, and is my preferred connection. 

Does this mean that high end cables are better? Sadly not necessarily. What one needs is good RF characteristics, and some expensive cables are RF poor. Also note that if it sounds brighter its worse, as noise floor modulation is spicing up the sound (its the MSG of sound). So be careful when listening and if its brighter its superficially more impressive but in the long term musically worse. At the end of the day, its musicality only that counts, not how impressive it sounds.         

Rob

Of course, you're welcome to make your own conclusions!

 

[397324]

Hi All
 
A quick question that I'm sure someone will have the answer to.
 
How does the Chord Mojo and FiiO X5ii combination combined with decent IEM's like the Sennheiser IE800's compare to higher end DAPS without additional amping with the same IEM's?
 
Regards
 
Darren

 

[AndrewH13]

Hi All

A quick question that I'm sure someone will have the answer to.

How does the Chord Mojo and FiiO X5ii combination combined with decent IEM's like the Sennheiser IE800's compare to higher end DAPS without additional amping with the same IEM's?

Regards

Darren

In my experience, better. Tried many alternatives including high end AK's to my Fiio X5/Mojo/ie800 combo and only the QP1R compares.

 

[MartynB85]

Do you guys think this can be used for your 'main' HP dac/amp?
 
I wanted something decent to use while on my pc but I can't decide on a desktop dac/amp. This gets so many praises I'm thinking of using it for my main setup, with the added benefit of being able to use it with my phone when out too. I could always add an amp later on and just use it's dac?
 
Thanks

 

[397324]

In my experience, better. Tried many alternatives including high end AK's to my Fiio X5/Mojo/ie800 combo and only the QP1R compares.

Funny, I have a QP1R!