[Takeanidea]

Another 4 hours spent listening to the Mojo through my HD800s yeserday.  Wow.... It's a shame I can't get one for myself , although like many of you I have spent my money with Custom Cables, doesn't look like they were in stock at the time of ordering despite it saying there were 10 in stock on their web site

 

[Skyyyeman]

 
 
Digital transmission is based on SPDIF standard which transmits data and clock information as an encoded signal usually using PCM, that information is decoded on the Mojo into data and clock signal so it's important that the encoded information be jittered free and not degraded over short distance.
 
The USB transmission on the other end is a device to device transmission mechanism using an encoding scheme and handshaking mechanism, it is usually stream based so more tolerant to poorer wire as frames are transmitted and decoded from the source to the target device. The target device will reconstruct the data and clock signal from the frame and then feed it to the DAC to be analog reconstructed and eventually band pass filtered to remove any residual high and low frequency signals out of the audio band.I still think you need to keep the USB cable short but it is more tolerant of longer lengths up to a limit.
 
To make a story short, the short USB cable is fine but an analog cable used as a digital one is just a bad idea. Again, that's just my opinion.

 




Thanks for your intelligent and lucid explanations. If you don't mind a related question:



Clock jitter -- What is clock jitter? The reason I ask is that in considering different DAPs to use as transports to output a digital signal to the Mojo, I've seen some varying specs for clock jitter on different DAPs, as follows:



AK100 90 ps (pico seconds)

AK120 50 "

AK240 50 "



Question: Does clock jitter degrade the digital signal before it's send out from the DAP? Or are they referring to clock jitter of the internal dac, in which case clock jitter doesn't matter since the signal never reaches the dac (it's been output beforehand)?



If clock jitter degrades the signal before it's sent out, then it appears that the AK100 is not as good a transport as the other two. But would the difference be discernible?



Thx

 


I think Rob Watts in effect answered the question in his post: "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."

 

[mscott58]

 
I don't think they know for sure as they have to make a special mold and that will take a little while. 

Cool. Thanks.
 
I already have the 2.2mm version for the back-to-back mount for the AK100, but might be interested at some point if this ultra-low works out of going for the "back-to-front" mounting. Can't imagine how small that cable would be, or if they could even make it. 
 
Cheers

 

[Torq]

Just wondering if any of you that had orders nominally slated for the 2nd batch (as delayed from last week) from Moon Audio have seen a shipping notification yet?

 

[musicheaven]

 
 
Digital transmission is based on SPDIF standard which transmits data and clock information as an encoded signal usually using PCM, that information is decoded on the Mojo into data and clock signal so it's important that the encoded information be jittered free and not degraded over short distance.
 
The USB transmission on the other end is a device to device transmission mechanism using an encoding scheme and handshaking mechanism, it is usually stream based so more tolerant to poorer wire as frames are transmitted and decoded from the source to the target device. The target device will reconstruct the data and clock signal from the frame and then feed it to the DAC to be analog reconstructed and eventually band pass filtered to remove any residual high and low frequency signals out of the audio band.I still think you need to keep the USB cable short but it is more tolerant of longer lengths up to a limit.
 
To make a story short, the short USB cable is fine but an analog cable used as a digital one is just a bad idea. Again, that's just my opinion.

 


Thanks for your intelligent and lucid explanations. If you don't mind a related question:

Clock jitter -- What is clock jitter? The reason I ask is that in considering different DAPs to use as transports to output a digital signal to the Mojo, I've seen some varying specs for clock jitter on different DAPs, as follows:

AK100 90 ps (pico seconds)
AK120 50 "
AK240 50 "

Question: Does clock jitter degrade the digital signal before it's send out from the DAP? Or are they referring to clock jitter of the internal dac, in which case clock jitter doesn't matter since the signal never reaches the dac (it's been output beforehand)?

If clock jitter degrades the signal before it's sent out, then it appears that the AK100 is not as good a transport as the other two. But would the difference be discernible?

Thx

AK are well know for low pico-second clock jitter (that's really really short), as usual in this instance, the lower the number, the better but remember what Rob just said it's going to be pretty much eliminated so I would think any of those players should work well. Jitter is actually created at the source and made worse over finite cable length which the target (DAC) needs to eliminate. There are different techniques to achieve that for example reclocking the clock signal to a reference the DAC uses, some internal electronics to that effect are called DPLL digital phase lock loop which job is to latch onto a clock signal using close loop feedback and feed it synchronously to the DAC so as it follows the encoded signal for analog extraction using phase demodulation. I'd be very surprise you're going to hear the difference using any of those players as long as your coax cable is short and well matched. The bottom line you don't want to create reflection that will make the jitter worse.

By the way I would look into getting a good optical cable with any of those players, as Rob said, optical is the preferred interface, at least no chance of using analog cables.

 

[rmillerx]

11/2 @ 5:00 Eastern. I am in US batch 2. Anxiously awaiting shipping notification on my mojo. (Unless there was a negating statement on here in the umpteen pages that I missed.). Hopefully November will start out great.

My AK 100mkII will be here just in time to be ready for the mojo if it ships on time.

 

[mscott58]

Happy hour with the Mojo stack! Cheers



You can see how even with the Mojo face-down the buttons don't touch the surface. The bands add a little extra cushion as well.

 

[rmillerx]

Actually, was never told officially that they would ship the same day as they arrived. So, hopeful let the distributor received them today and hopefully I will get a notification that my mojo has shipped in the next day or two.

I am looking forward to this device more than any I can remember.

 

[singleended58]

Just wondering if any of you that had orders nominally slated for the 2nd batch (as delayed from last week) from Moon Audio have seen a shipping notification yet?

 


When did you order? I have not seen any notifications of 2nd batch since I believe my order was received on 10/15/15 in the afternoon. What is about yours?

 

[KT66]

Pics of Z5 or it didn't happen.

tomorrow.

 

[Black Dog]

This may start a heated discussion but to me Tidal, Spotify or any streaming service is not a viable alternative to actually owning the album if you are serious about the music. My opinion has nothing to do with the technical aspects of using the Mojo with a streaming service and possible radio frequency interference but comes down to one unassailable issue, mastering.

I have and continue to buy albums I already own again because the master is the most important link in the chain of music. With streaming services you have no idea of the master or who mixed it. Right now I have preordered two albums that I already own simply to get a new remix (Fragile by Yes and Damnation by Opeth both Steven Wilson remixes). In my experience, higher resolution is far far less important than the master or remastering and ceding control to a third party streaming service is foolish.

Yeah, in the ideal world it would be great to own all the music that moves you. For me, with around 900 CD's, it feels like I barely scratched the surface.
You are spot on about mastering quality being the most important link in the chain of music. So my short time strategy will be to research my new music through books & internet, evaluate  the alternatives through Tidal and take it from there to make a buying decision.
So how does the combination of Tidal on an Android phone, in my case Sony Xperia Z5C, mated with the Mojo, fare.
Here in Holland LTE/4G has effectively been rolled out.

 

[singleended58]

Actually, was never told officially that they would ship the same day as they arrived. So, hopeful let the distributor received them today and hopefully I will get a notification that my mojo has shipped in the next day or two.



I am looking forward to this device more than any I can remember.

 


I think the 2nd batch will arrive today but do not know exact time (?). My AK100 Mk2 is going to be here on Wednesday 11/4/15 and I am still awaiting my MOJO???

 

[musicheaven]

Actually, was never told officially that they would ship the same day as they arrived. So, hopeful let the distributor received them today and hopefully I will get a notification that my mojo has shipped in the next day or two.



I am looking forward to this device more than any I can remember.

 


I think the 2nd batch will arrive today but do not know exact time (?). My AK100 Mk2 is going to be here on Wednesday 11/4/15 and I am still awaiting my MOJO???

At least you can still listen to your AK while the Mojo crosses the pound on a long boat voyage.

 

[McCol]

Any UK folks imported an AK100mkii from the US? Some good prices and thinking would get stung approx £65 for taxes, would that be about right?
Would make it total around £350 which is around £250 cheaper than I can find in the UK.

Want to give it a crack with the Mojo.

 

[musicheaven]

At think you guys gotta think which DAC on your AK you'd want to get in the case where you forget your Mojo home (lol).