[elwappo99]

Mine finally showed up. Got the drivers hooked up and looks like it's all up and running. 

 

[conquerator2]

Mine DI-V2014 arrived too. It joined the Wyrd to expand my desk's collection of boxes and gizmos

I've been feeding the NFB7 via HDMI through it and everything is fine.
The only difference I've noticed is that it now clocks all signal to 24bit, while the regular NFB7 USB input clocks it at 32bit. No SQ difference though, the DI-V2014 does what it should and it also passes DSP [AC-3/DD5.1], which is something not every device does [the OR5 for example, doesn't].
Zero issues for now, coupled with the NFB7 :} 

 

[elwappo99]

  Mine DI-V2014 arrived too. It joined the Wyrd to expand my desk's collection of boxes and gizmos

I've been feeding the NFB7 via HDMI through it and everything is fine.
The only difference I've noticed is that it now clocks all signal to 24bit, while the regular NFB7 USB input clocks it at 32bit. No SQ difference though, the DI-V2014 does what it should and it also passes DSP [AC-3/DD5.1], which is something not every device does [the OR5 for example, doesn't].
Zero issues for now, coupled with the NFB7 :} 

 
Perfect! 
 
Now we just need to live in the same side of the planet and we could compare! 

 

[conquerator2]

Perfect! 

Now we just need to live in the same side of the planet and we could compare! 

Well, I go to L.A. regularly, cause my brother lives there
Certainly a future posibility.
I might give the U12 a try in the future anyway but for now I like the sound.
I wpuld think the U12 (or its XMOS chip) gives a smoother sound than the V2014.
Or not. We might see

 

[Failed Engineer]

Just bought a U12 to pair with a vintage DAC I just purchased with an AES/EBU balanced input.  It seems to be well regarded and appropriately priced for an experiment so I pulled the trigger.  The AES/EBU output on the U12 is not common on other USB transports so it was the final selling point.  Looking forward to posting my thoughts.

 

[preproman]

  Mine DI-V2014 arrived too. It joined the Wyrd to expand my desk's collection of boxes and gizmos

I've been feeding the NFB7 via HDMI through it and everything is fine.
The only difference I've noticed is that it now clocks all signal to 24bit, while the regular NFB7 USB input clocks it at 32bit. No SQ difference though, the DI-V2014 does what it should and it also passes DSP [AC-3/DD5.1], which is something not every device does [the OR5 for example, doesn't].
Zero issues for now, coupled with the NFB7 :} 

That sounds promising Luke..  

 

[Benny-x]

   
The U12  uses a 45MHz and 48MHz crystal, these are readily available at Mouser or Digikey, however they do not stock the femto clocks at these frequencies.
I modded an older unit similar to the U10 using the Crystek CCHD-957 this is a 500fs jitter device, the ones that are advertised as the femto clock upgrades are typically the Crystek CCHD-575 (82fs) or Abracon ABLNO (100fs) .
 
If you know of a source willing to sell small quantities of these devices at the required frequencies, I would be most interested.
 
(I have been experimenting with the femtos on the Yulong DA8 DAC, and there are some pictures of them on the DA8 review thread for anyone curious about them)

I found a local'ish, also taobao.com, spot where I can buy the same Crsytec CCHD-957 clocks that you used, so I'm going to go ahead and buy the Gustard and try the clock upgrade. There's no way the internal clocks are going to be better than those Crsytek ones... I really wish I could find the CCHD-575 units in 45.1584MHz and 49.152MHz like this convertor takes. The 22-25MHz versions are super easy to find, but not these 2 :'-(  I would also be really interested in buying some if anyone knew where to get them.
 
And on page 4 RB2013 also did a filter cap mod, replacing the standard 2200uf Phillips caps with the same rated Panasonic FC ones. I'm gonna give this a shot too, but I'd like to up the capacitance a little as I've had good results doing so on other components. I haven't decided on which caps I'd like to go with or what values, though. I've only ever used Nichicon and Mundorf before. I've heard Elna Silmic II's are good, but would anyone have any application specific ideas for here?
 
Ah... down the rabbit hole I go again

 

[preproman]

WOW Ben,  Let us know how it turns out.  I will be sending you one to mod for me (maybe) 

 

[Benny-x]

  WOW Ben,  Let us know how it turns out.  I will be sending you one to mod for me (maybe) 

Will do. The modding part will take a little while to get around to, but collecting the parts shouldn't be bad.
 
As for sending a unit for me to mod, no problem! I take payment in Master 7s...

 

[preproman]

  Will do. The modding part will take a little while to get around to, but collecting the parts shouldn't be bad.
 
As for sending a unit for me to mod, no problem! I take payment in Master 7s...

Ha ha ha ha...  It's going up for sale soon...

 

[Benny-x]

You're kidding? Why? I know you've got the AMR-777, but are you thinking of replacing them both?
 
With the new HDMI-I2s input board and all the stuff going on about disconnecting PLL, changing the upsampling, and whatever else, it seems like the DAC is only getting better. And with the 8x PCM1704UK making it a real modern R2R DAC, I can't see any reason to sell it. I don't have any means to pick one up, but it's really been on my mind since that HDMI-I2s upgrade came out.
 
I guess I've wanted to try Kingwa's reference DAC since I found out about the Ref 1, 8, and 9 several years ago. I never ever had the cash at the right time and never went to a meet to hear one, and now the Master 7 has the feedback to say it's the best of his crop so far. If I had one, even if it sat backseat somehow, I don't think I could sell it. Even if by PM, you've got to bring me up to speed on that one. 

 

[rb2013]

  So, did you guys ever come to a conclusion of what to do about the transformer? Did we find out if it's got the standard wiring or if the primary and secondary are switched/proprietary? It looks like a cool and not too challenging mod, so I'd love to give it a shot if you guys settled it.
 
Thanks.

Hey Benny-x - Very cool you're in China - some really amazing audio.  You should hear the modded Bada 3.3SE Purer with Mundorf Silver Gold caps - the best Class A amp I've ever heard.  I have two of the old versions with the Toshiba outputs and 6922s pre amp tube (same as my Lite DAC60).  Magical with my Holy Grail tubes!
 
Well I never heard back on the transformer issue - I do believe it's switched and proprietary.
 
Getting the wiring wrong on that mod would be a horrible sight!  Unless you like fireworks

 

[rb2013]

  I found a local'ish, also taobao.com, spot where I can buy the same Crsytec CCHD-957 clocks that you used, so I'm going to go ahead and buy the Gustard and try the clock upgrade. There's no way the internal clocks are going to be better than those Crsytek ones... I really wish I could find the CCHD-575 units in 45.1584MHz and 49.152MHz like this convertor takes. The 22-25MHz versions are super easy to find, but not these 2 :'-(  I would also be really interested in buying some if anyone knew where to get them.
 
And on page 4 RB2013 also did a filter cap mod, replacing the standard 2200uf Phillips caps with the same rated Panasonic FC ones. I'm gonna give this a shot too, but I'd like to up the capacitance a little as I've had good results doing so on other components. I haven't decided on which caps I'd like to go with or what values, though. I've only ever used Nichicon and Mundorf before. I've heard Elna Silmic II's are good, but would anyone have any application specific ideas for here?
 
Ah... down the rabbit hole I go again

The Elna Silmic II are awesome 'lytics - used a bunch in my Lite DAC60 stage 2 and 3 mods. They are a little more musical and less neutral then the FCs.  I believe the FCs have a longer life rating and higher temp range - which shouldn't be an issue in the U12.
 
As for femto clock mod - it may not have as big of an effect in the U12 based on the way the Xmos chip utilitizes the external clocks.  Checkout the posts 83, 84,...etc back on page 6.  But you never know - from what I've read the M2Tech Evo was improved by external clocking - but that was an entirely different chipset and implementation.  To bad the U12 didn't have an external clock capability.  I'd like to try one of these
 
http://www.frontendaudio.com/Antelope-Isochrone-10M-Master-Clock-p/9999-15889.htm?gclid=Cj0KEQiA8f6kBRCGhMPFtev8p58BEiQAaMLmqfxlIKVL6U5I2oJ-6ZVlWeTnMpySGBNzUU-y-167RgsaAljq8P8HAQ&click=18920
 
Joking of course!  But there is the cheaper Evo clock - http://www.spearitsound.com/Digital_Clocks-M2Tech_EVO_Clock.html?gclid=Cj0KEQiA8f6kBRCGhMPFtev8p58BEiQAaMLmqWZApg5xoQgF72k6Tdwhtv4wMYQufRn1DWmrQNK4dKMaApSs8P8HAQ
 
Anyway back to the Gustard U12 and the Xmos clocking implementation:

  I posted there this question and received this reply
On the XMOS clocking issue, I believe you described the clock derivation issue as:
“And according to this doc [link], the input clock (say the 24.576MHz clock) is sampled to the internal processor clock. Meaning that the external clock ticks (or transitions) are mapped to the processor clock ticks. This means that the worse “jitter” is when you just miss the external clock transition and must wait for the next internal clock tick. So the worse deviation from the actual frequency is the period of the processor frequency, thus for a 400MHz internal clock part, it is 2.5nS. This is the peak jitter. Thus the RMS number is 2.5/SQR(2)=700 psec””

Was this just a implementation of the XMOS on this particular DIYINHK board using the C7424Z chip, or is it implicit to designing around the XMOS? Sounds that way.

Although it was mentioned by HML that “The Xmos processor data sheets suggest that it may be possible to use the MCLK for the clock source for the BCLK and LRCLK. This is not done in the reference design and not in the DIYINHK board.”

I will post closeups of the Gustard U12 board when I get it.



 


 

1. 

   
   
   BlgGear
   ​
   2014/10/07 at 17:52
   Reply
   I don’t recall completely, but I think this is inherent in the XMOS chip.
   
   
   
   
   

 

[b0bb]

  I found a local'ish, also taobao.com, spot where I can buy the same Crsytec CCHD-957 clocks that you used, so I'm going to go ahead and buy the Gustard and try the clock upgrade. There's no way the internal clocks are going to be better than those Crsytek ones... I really wish I could find the CCHD-575 units in 45.1584MHz and 49.152MHz like this convertor takes. The 22-25MHz versions are super easy to find, but not these 2 :'-(  I would also be really interested in buying some if anyone knew where to get them.
 
And on page 4 RB2013 also did a filter cap mod, replacing the standard 2200uf Phillips caps with the same rated Panasonic FC ones. I'm gonna give this a shot too, but I'd like to up the capacitance a little as I've had good results doing so on other components. I haven't decided on which caps I'd like to go with or what values, though. I've only ever used Nichicon and Mundorf before. I've heard Elna Silmic II's are good, but would anyone have any application specific ideas for here?
 
Ah... down the rabbit hole I go again

Mouser ships to China, all 4 of the audio versions (22MHz, 24MHz, 45MHz, 49Mhz)
http://www.mouser.cn/Search/Refine.aspx?Keyword=cchd-957

 

[b0bb]

   
 
Well I never heard back on the transformer issue - I do believe it's switched and proprietary.
 
Getting the wiring wrong on that mod would be a horrible sight!  Unless you like fireworks

My U12  got lost in transport, seller refunded payment but it ended up taking 5 weeks, in the meantime I got caught up in other stuff.
 
I will probably get another unit in early 2015