[Wyd4]

 
In computer-based digital systems, particularly storage, the data is transmitted with checksums, which allow for detection of errors, and also with re-transmit schemes so that when an error is detected the block or packet of data can be rejected and another copy is sent.
 
That doesn't happen with any digital audio standard, electrical or optical, except for with HDMI audio (which has it's own special set of issues).
 
There's NO error detection and NO re-transmit option.
 
With an error-corrected digital transmission a poor, or sub-spec (or run that is too long), cable will first result in slower transmission ... as more errors occur and have to be corrected and, eventually, will either overwhelm the error-correction mechanism, or simply fault out from too many errors per second to maintain a useful connection.
 
Remember that in "digital" systems, the ones and zeroes are simply modulated analog voltages.  Depending on the slew rate of the transceiver, and the capacitance of the conductive medium that joins them, it becomes progressively harder to delineate between a 0 (typically 0 volts) and a 1 (typically 5 volts).  At audio data rates this isn't too much of a problem, but at higher frequencies it rapidly becomes so.  You can wind up with a signal that looks, from the receiver's perspective, more like 1.5 volts and 3 volts (I'm exaggerating to make a point) - which is only 1/3rd the potential difference between 1 and 0 that the spec calls for ...
 
Different metals have different conductive properties (attenuation/resistance, capacitance).  Different dielectrics (the insulator on the cable) also have different properties.  And, most importantly, shielding has an effect on the cable too ... good and bad ... while it helps reject noise, it typically adds capacitance.  Depending on your circuit that may be irrelevant or it may be catastrophic.  These factors can exacerbate other issues.
 
In short, since digital audio standards are actually analog voltage modulations, with no error correction, and cables have the ability to capture, transmit and radiate/inject noise into a receiving circuit, there's a great deal of potential variance in any cable and any transmit/receive pairing.
 
One easy way around this is to use an optical connection; however, there is no such thing as a free lunch and there are issues here too.
 
Using a simple RAM buffer on the receiver, with an error-corrected/re-transmitting protocol, would fix most of the issues, at the cost of some playback/control latency.  Of course, again, there are no free lunches, and there are similar issues that can occur between such an internal RAM buffer than the sensitive electronics in, say, a DAC (especially on the analog side of the circuit).

 
Thanks for that.  Much more detail than I was expecting.

Makes sense.  As I said previously I heard a difference.  I knew it was there.  Now this in conjunction with both @x RELIC x and Rob's posts I have a better idea as to why.

CHeers!
 
And because I steered this off topic, 
 

 
I do so love my Mojo

 

[Torq]

   
Thanks for that.  Much more detail than I was expecting.

Makes sense.  As I said previously I heard a difference.  I knew it was there.  Now this in conjunction with both @x RELIC x and Rob's posts I have a better idea as to why.

CHeers!
 
And because I steered this off topic, 
 

 
I do so love my Mojo

I'm generally super-skeptical about any product that receives as much hype as the Mojo did, and has.  Hell, my first comments about it, prior to hearing it, were not particularly nice (though they were limited to the aesthetics, which have since completely grown on me).
 
I admit I got caught up in that hype, despite my best intentions, and went out of my way to secure a unit as early as possible.  From the first time I've fired it up I have not been at all disappointed.  In fact, that's not fair - that'd be damning the Mojo with faint praise.  In reality I think the little guy is spectacular.  Not just for it's price, but in general.
 
I find that it easily bests the entire AK line-up (I've not heard the 380 Cu, so we'll except that for now).  It drives headphones that require serious power with aplomb.  I haven't found anything shy of my LCD-4 and Abyss that it doesn't drive well.  And in the big high-end DAC shootout/audition I'm doing, it has completely embarrassed DACs costing many times it's bargain price.
 
I'm on record, in this thread and others, as thinking the Mojo sounds better than the Hugo.  I'm not saying I think it's technically better ... but of the two I'll keep the Mojo.  So I AM saying that I definitely prefer the sound via the Mojo to the Hugo.  Though I would be interested in a  USB-chargeable version of the Hugo (with the Mojo's noise levels ... since it seems to exhibit less hiss than the Hugo with my very-sensitive IEMs).

 

[x RELIC x]

Hahah while I understand it is not literally 1 and 0, but in one way shape of form derived from that theory, on off, current pulses etc.

But to use the 1 and 0 in a literal sense, are you telling me say a copper cable may send 1 and 0, however a gold cable may send .5 and 0? (I know we aren't literally seeing numbers)
Or perhaps the entire 1 makes its way from one end to the other, however does so slower.  But wouldn't this mean ALL 1's do so slower?  If so what difference would this make?

I have always been of the opinion that better digital cables are better, but only in terms of bandwidth eg poor HDMI cable not capable of transmitting the data required to sustain 1080p for example (or 4k in todays world, man I am getting old )

To use the HDD as an example, positive and negative.  I store a movie.  I store the same movie on an SSD.  Both have ample cache/speed to deliver the movie file to my GFX card to be decoded and turned to video and then output to my monitor.  Both movies look and sound identical.  What differs between this example and your explanation?

I am not disagreeing with you as such, just interested. As to my lack of knowledge, all things would work out equal, whether it be all slower or all faster, unless there were some sort of change to digital data through introduction of something external or data loss entirely.

Baring in mind small words would be good as know nothing about electronics hahaha


*** EDIT *** Please note that I say the above, having heard first hand their is a difference, so not defying you in aid of an argument

Movies aren't converted to analogue now a days, it's still digital sampled data we see on the screen, through pixels, although the emitted light that shines through the LCD or illuminated by plasma/OLED is of course an analogue medium, just not analogue for the different pixels representing the original image. In that case it's a bit different from audio so sort of not comparable.

What I meant was even though you may get data throughput from a cable you also have the distinct possibility for said cable to pick up noise or have an impedance mismatch between sources. Theses occurrences, just a couple for example, can have a very real effect to what we hear given that the storage and transmission of represented 0's and 1's in the real world can be affected by other influences along the way to our ears.

Torq explained the various digital audio complexities very well.

 

[Rob Watts]

First off, sorry if this has been mentioned before. I checked post 3 and nope, it's not there under interviews, and quite frankly I'm not going to trawl through the 1.25 thousand pages that this thread has just to see if somebody else has mentioned it.

Flicking through some HiFi sites over the weekend I found this guide to digital audio from HiFi+, which contains a very informative interview with Mr Rob Watts himself. Although the interview doesn't mention the Mojo, it mentions the Hugo and Dave, it is nevertheless relevant to Mojo, and is well worth a read.

It's a freebie PDF download that you can get here - http://www.hifiplus.com/buyers_guides/2/ Page 56 is where the action starts.

It's good to see him voicing discontent with the DSD format, although he criticises it for technical reasons, whereas I dislike it for practical reasons.

Mython - maybe this link might be good on post 3, even though Mojo is not directly mentioned.

Yes I did not want to over egg the pudding re DSD's practical problems - as its apparent to anybody that has DSD audio. By far the biggest problem is size - I have a 5 min DSD 512 sample and its 2GB! Size is a big issue for me, as my 4TB portable hard disk is full - and I want to buy some more classical box sets. So to have a format that is too big, and sounds unnaturally soft and flat (even DSD512) is just plain crazy.
 
I was in Japan earlier this year, being interviewed by half a dozen Japanese reviewers. They all asked me what did I think about DSD. Nervous pause on my side, as I like to be polite, and the Japanese are extremely polite, and DSD is very big in Japan. So I would carefully answer that I do not like DSD, that to me it sounds soft with a flat sound stage. To a man they said, yes I agree, but DSD is big in Japan! Then we would both laugh.
 
So my criticism is technically based, as that's a perspective I can add something with.
 
Rob 

 

[Arpiben]

Movies aren't converted to analogue now a days, it's still digital sampled data we see on the screen, through pixels, although the emitted light that shines through the LCD or illuminated by plasma/OLED is of course an analogue medium, just not analogue for the different pixels representing the original image. In that case it's a bit different from audio so sort of not comparable.

What I meant was even though you may get data throughput from a cable you also have the distinct possibility for said cable to pick up noise or have an impedance mismatch between sources. Theses occurrences, just a couple for example, can have a very real effect to what we hear given that the storage and transmission of represented 0's and 1's in the real world can be affected by other influences along the way to our ears.

Torq explained the various digital audio complexities very well.

Completing the explanations above:

1. A bad or defective USB/SPDIF cable or fiber will generate transmission errors. Depending on Bit Error Rate and/or position in the packet you will have distortions,clicks,pops or no audio output at all.

2. A standard USB/SPDIF cable or fiber should be free of transmission errors for specified throughput.

3.An enhanced USB cable will add better RF rejection. A better fiber will mainly allow to reach the maximum throughput.

 

[Delayeed]

I just got my cheapo 10$ optical cable and from first testing I think I'm hearing more bass impact vs USB, will continue testing.

 

[audi0nick128]

Hey there,

Just when I thought the thread stalled (I noticed that there was a a whole day without reply) , there are great informative posts coming in from all directions
I would like to participate, by sharing impressions of my Pi music server, but I am still struggling with wlan implementation for the Pi running runeaudio and due to the placement of my router I was only able to confirm that it works with mojo... Kind of hard to do critical listening, when you have to do gymnastics, as well.
Seems like I managed to kill the build in wlan module of pi 3... Anyway, I will possibly switch over to odroid C2, but my first DIY efforts where kind of discouraging. If someone plans something similar without any experience, I strongly advise to follow the instructions of choice slavishly without any tweaks.

BTW has anyone heard Mojo with Fostex Purple Hearts, yet?

Cheers

 

[sanakimpro]

edit: solved with 3rd post

 

[x RELIC x]

I realized that when I first plugged in the charger to the Mojo for the first time, I heard a soft whirrr, akin to a computer fan. Is there a small fan in there?! After like 10 seconds, the sound stopped. Anyone notice something similar?

Yes, everyone. Please read the battery section in the third post. :wink_face:

 

[Light - Man]

   
Thanks for that.  Much more detail than I was expecting.

Makes sense.  As I said previously I heard a difference.  I knew it was there.  Now this in conjunction with both @x RELIC x and Rob's posts I have a better idea as to why.

CHeers!
 
And because I steered this off topic, 
 
 
 
I do so love my Mojo

 
I will help row you back in the right direction!
 
Does your other half know about this Mojo affair???

 

 

[rynogee]

Sorry if this has been answered, but not that clear from searching many thousands of pages
 
Is there any good/preferred higher quality USB on the go (OTG) cable for android devices people have found, preferably with L shaped ends at both ends. I saw an audio technica one somewhere in the thread but it didn't have L shaped (90 degree) ends.
 
thanks

 

[audi0nick128]

Sorry if this has been answered, but not that clear from searching many thousands of pages

Is there any good/preferred higher quality USB on the go (OTG) cable for android devices people have found, preferably with L shaped ends at both ends. I saw an audio technica one somewhere in the thread but it didn't have L shaped (90 degree) ends.

thanks

Check post 3 for different options.
I am very happy with my Cable by Forza Audio Works from Poland.
You can ge a Cable tailored to your needs.

Cheers

 

[music4mhell]

 

Sorry if this has been answered, but not that clear from searching many thousands of pages

Is there any good/preferred higher quality USB on the go (OTG) cable for android devices people have found, preferably with L shaped ends at both ends. I saw an audio technica one somewhere in the thread but it didn't have L shaped (90 degree) ends.

thanks

Check post 3 for different options.
I am very happy with my Cable by Forza Audio Works from Poland.
You can ge a Cable tailored to your needs.

Cheers

Do you have any other cable other than Forza ones ?

 

[rynogee]

thanks, now avoiding asking various other questions probably answered in the well sign posted post 3...

 

[enthusiast]

Hi, I received my Mojo today - thanks to Auditorium - highly recommended German Webshop! There is a problem when plugged to my Macbook 12 (2016 Core M5), lotsa clipping, and I mean constantly. Does the Mac have not enough CPU? Dual Core 1,2GhZ should do it imho. Any help is appreciated.