[Jmask5]

It seems on paper like it would be a good pair but I don't see too much impressions if any. Even with the TH900 not too much. 

 

[Delayeed]

I am not doubting that a lot of work has been done.
Unfortunately I was hoping that the module would appear last Easter, when it would have been useful on my commute.

Every time that JF or RW has started discussing the 'module', the vision has changed yet again. It started as a simple SD card holder, then a screen got added into the design, and now JF is talking about a mystery device, with amazing , but undefined, functionality.
To anyone experienced in product development, this sounds like a classic case of 'requirements creep', where the product requirements get constantly updated, leading to continual rework of the product design. Inevitably the product release date keeps slipping to the right.

I am eagerly awaiting the announcements at CES, but I need something to look forward to at Christmas.

Wait, what? There's a player add-on coming? I remember seeing something like that being talked about like half a year ago but I thought it wasn't going to be a real product.

 

[sling5s]

Need some help. I'm looking for a USB to Coaxial Adapter for the Mojo to iPhone.
I find the USB out of Mojo to be thin and brighter than Optical and Coaxial.
So I'm wanting to use the USB to Coaxial adaptor and connect the Mojo via coaxial instead of USB from iPhone (camera kit).
I'm wondering if the Audio S Redkey or any other budget USB to Coaxial adaptor will work with iPhone and not just PC or Mac.

 

[GreenBow]

There's a new pair of headphones been reviewed by What Hi-Fi and paired with the Mojo, and an LG G5. The B&W P9 Signature.
 
This is the review of the headphones. http://www.whathifi.com/bw/p9-signature/review
 
In the magazine they say use with the Mojo and G5.
 
Just saying.

 

[jwbrent]

  Wait, what? There's a player add-on coming? I remember seeing something like that being talked about like half a year ago but I thought it wasn't going to be a real product.

I'm interested in this module and the DNLA module.

 

[Delayeed]

My Mojo has been shutting down on its own again. Blinking white for 1 second then 3 short red blinks then repeats that until it shuts down.
I've tried 2 different USB cables to charge from my PC and also a 1.2A wall charger.

It's also not thermal throttling since the thing isn't warm.

Sometimes when I keep replugging the charging cable it stays on and shows white light non blinking. But then after like 10 hours or so goes back to retard mode and shuts down and starts blinking. (To clarify the blinking is the battery light not the balls)

Any help appreciated...

 

[miketlse]

I'm interested in this module and the DNLA module.

There may be only one multifunction module - the clues from Chord have been necessarily a bit cryptic.

 

[jmills8]

There may be only one multifunction module - the clues from Chord have been necessarily a bit cryptic.

Well they dont want to promise a date cause they want to release it by mid December 2016......... I made this up, just wishful thinking.

 

[Andrei Sprogis]

MOJO is one of the greatest portable amps ever created...
When I just bought it, i was slightly dissapointed, because the sound was cold and sharp.
But after the connection to my MacBook and warming it up for a while, the results were completely opposite.
It's like a drug. Want to use it more and more each day

 

[Rob Watts]

 

  @GRUMPYOLDGUY
 
Thanks for your reply, actually am with  @RPB65 ,  do elaborate and help me grasp  the context better, please.

 
Sorry, my last few posts weren't particularly useful... Here's a better explanation.
 
Mojo uses digital attenuation, where each click of the volume button results in a 1dB change in output level. Because it's done digitally it is effectively a scale factor applied to the audio samples:
 
-1dB = 10^(-1/20) = ~0.8913x
+1dB = 10^(1/20) = ~1.1220x
 
Because we're talking about fixed point math here, there is some quantization error involved meaning these constants will not be exactly 10^(-1/20) or 10^(1/20)... but we can ignore that for the purposes of this discussion since it's ancillary to the real problem with digital volume control. 
 
When we scale the audio samples, we have discrete control... This requires a crash course on fixed point math. If I multiply two 32-bit numbers with, say, 30 fractional bits, I need 64 total bits with 60 of those being fractional to store the result with no loss of precision. Of course this bit growth can get out of control really quickly, so we use rounding at strategically chosen stages that balance precision with area (i.e. resources in the FPGA). If we're using a 32-bit DAC, no matter what, we have to reduce samples to 32 bits. The problem is I can only get so close to 0 without actually being at zero... specifically 32'h1 (+1) or 32'hFFFFFFFF (-1). So even if the math says a particular sample should be even closer to zero than 1/2^30, I can't achieve it digitally. Consequently, I lose a bit of information (pun totally intended). 
 
In the analog world this isn't problem... we have infinite control over amplitude from rail to rail and can get as close to zero as we like. Of course the reality is things like noise performance limit how small of a signal we can produce that is still meaningful, but that problem exists regardless of whether we use digital volume control or analog volume control. So analog volume control is the better option in terms of preserving information.   

If I were to use rounding then what you say is correct, there would be small signal non-linearity.
 
But Mojo categorically does not use anything as crude as rounding to convert bit depths as the volume function is running at 16FS (705.6 kHz or 768 kHz) - I use extensive noise shaping to change bit depths. Mojo's noise shaping from beginning to end through all the intermediate paths (that is digital input to the 4e pulse array outputs) ensures 200 dB performance in band - that's better than 32 bit performance. The benefit of this is small signal non-linearity is much better, and this is essential for depth perception - the tiniest error in small signal amplitude, no matter how small, is audible in terms of truncation of perceived depth of sound-stage.
 
Your assertion that analogue does not have these problems is incorrect. Any metal to metal interface contains oxides and other impurities - and copper oxide is diodic, and so attenuates small signals and creates small signal distortion. Moreover, carbon track volume controls are also non linear, as carbon composition has significant voltage dependency of resistance - another source of non-linearity. Analogue electronics additionally suffer from RF noise pick-up, which when added to an active stage will then create more noise floor modulation due to audio signal and random RF noise inter-modulation.
 
Mojo, unlike all other non Chord DAC's, has no measurable noise floor modulation, and zero distortion of small signals, with no measurable fundamental signal non-linearity. This is not something that other DAC's can do, nor is it something that an analogue volume control can do too. And the benefit of all this is refinement and transparency - key ingredients for musicality.
 
Rob 

 

[citraian]

My Mojo has been shutting down on its own again. Blinking white for 1 second then 3 short red blinks then repeats that until it shuts down.

I've tried 2 different USB cables to charge from my PC and also a 1.2A wall charger.


It's also not thermal throttling since the thing isn't warm.


Sometimes when I keep replugging the charging cable it stays on and shows white light non blinking. But then after like 10 hours or so goes back to retard mode and shuts down and starts blinking. (To clarify the blinking is the battery light not the balls)


Any help appreciated...

Same thing just started happening to me...
Using an Anker charger here.
Out of nowhere it shuts down and the charging led starts blinking. If I replug, the charging led doesn't blink and the mojo will work for some time just to randomly shut down and blink at some point...

 

[GreenBow]

Question is....does the Mojo outperform the new Audiolab M-DAC+?
 
I think just and probably. Haha.

 

[jmills8]

Question is....does the Mojo outperform the new Audiolab M-DAC+?

I think just and probably. Haha.

portable? Compare it to the

2Qute.

 

[ThomasHK]

  If I were to use rounding then what you say is correct, there would be small signal non-linearity.
 
But Mojo categorically does not use anything as crude as rounding to convert bit depths as the volume function is running at 16FS (705.6 kHz or 768 kHz) - I use extensive noise shaping to change bit depths. Mojo's noise shaping from beginning to end through all the intermediate paths (that is digital input to the 4e pulse array outputs) ensures 200 dB performance in band - that's better than 32 bit performance. The benefit of this is small signal non-linearity is much better, and this is essential for depth perception - the tiniest error in small signal amplitude, no matter how small, is audible in terms of truncation of perceived depth of sound-stage.
 
Your assertion that analogue does not have these problems is incorrect. Any metal to metal interface contains oxides and other impurities - and copper oxide is diodic, and so attenuates small signals and creates small signal distortion. Moreover, carbon track volume controls are also non linear, as carbon composition has significant voltage dependency of resistance - another source of non-linearity. Analogue electronics additionally suffer from RF noise pick-up, which when added to an active stage will then create more noise floor modulation due to audio signal and random RF noise inter-modulation.
 
Mojo, unlike all other non Chord DAC's, has no measurable noise floor modulation, and zero distortion of small signals, with no measurable fundamental signal non-linearity. This is not something that other DAC's can do, nor is it something that an analogue volume control can do too. And the benefit of all this is refinement and transparency - key ingredients for musicality.
 
Rob 

I love how you take the time to come in here and correct false assumptions. Really learning a lot from all your input. Your piece on subjective testing was very informative and I'm sure I'll use parts of it in my day job (headphones engineer).
 
On several occassions I've seen you mention that small signal modulation or non-linearity is introduced due to injected noise. Does this show up on IMD measurements, THD for very small level test signals, both or do you have to assess this somehow else?

 

[betula]

  My Mojo has been shutting down on its own again. Blinking white for 1 second then 3 short red blinks then repeats that until it shuts down.
I've tried 2 different USB cables to charge from my PC and also a 1.2A wall charger.

It's also not thermal throttling since the thing isn't warm.

Sometimes when I keep replugging the charging cable it stays on and shows white light non blinking. But then after like 10 hours or so goes back to retard mode and shuts down and starts blinking. (To clarify the blinking is the battery light not the balls)

Any help appreciated...

Very much sounds like a charger issue. PC USB ports usually do not have enough power to charge Mojo, so do not even bother with that. I would try a different wall charger (another 1A+ one).