Go Back   Home > Forums > Source & Line > Digital Line Level

Digital Line Level DACs, Digital Crossovers, Equalizers, etc.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 19th April 2012, 09:17 AM   #401
zinsula is offline zinsula  Switzerland
diyAudio Member
 
zinsula's Avatar
 
Join Date: Mar 2004
Quote:
Originally Posted by vzs View Post
[...]With 4 trailing clocks only PCM1702 would benefit of the stopped mode operation while for PCM1704 would be similar to continuous clock mode.
As PCM1704 is the newer and seems to be used by more diyers I would better support this - so to have 2 trailing clocks. But it's all one for me.
[...]
Fully agree, PCM1702 users could use the continuous clock operation.
Sometimes, compromises must be made, and this one is a small compromise, as LE and DATA are quiet anyway during conversion also with continuous clock.
__________________
If you can't trust your ears, then CLICK HERE
  Reply With Quote
Old 19th April 2012, 10:45 AM   #402
diyAudio Member
 
andrea_mori's Avatar
 
Join Date: Jan 2005
Location: Italy
Quote:
Originally Posted by iancanada View Post
Hi guys, you made very good points

7, Do you think this little convertor board need support an optional 'SONY' format beside the default I2S format?

Cheers,
Ian,
I think so, if that help me to interface with NPC SM5842.
Thanks
Andrea
  Reply With Quote
Old 19th April 2012, 12:05 PM   #403
diyAudio Member
 
andrea_mori's Avatar
 
Join Date: Jan 2005
Location: Italy
Default Master clock

Ian, friends,

a few years ago I bought an XO3 from Guido Tent, to use it to reclock CD PRO SPDIF, but if I'll feed directly FIFO buffer from CD PRO I2S data it become available for other applications.
Do you think that I can use XO3 as master clock in FIFO buffer?

Anyone has thought to use a PLL?

Andrea
  Reply With Quote
Old 19th April 2012, 03:54 PM   #404
zinsula is offline zinsula  Switzerland
diyAudio Member
 
zinsula's Avatar
 
Join Date: Mar 2004
Has the XO3 a VCXO / PLL? In that case, don't use it. The FIFO will be there to correct small frequency deviations.

PLL, being software or hardware, will have to lock on the incoming stream. So it will need either a VCXO (which has worse phase noise performance than a comparable XO) or a software solution with clock dividers and who knows what.

It's no way better than a FIFO with independent clocks (but they of course must be close enough in frequency not to overfill or empty the FIFO buffer).
__________________
If you can't trust your ears, then CLICK HERE
  Reply With Quote
Old 19th April 2012, 04:20 PM   #405
diyAudio Member
 
andrea_mori's Avatar
 
Join Date: Jan 2005
Location: Italy
Quote:
Originally Posted by zinsula View Post
Has the XO3 a VCXO / PLL? In that case, don't use it. The FIFO will be there to correct small frequency deviations.

PLL, being software or hardware, will have to lock on the incoming stream. So it will need either a VCXO (which has worse phase noise performance than a comparable XO) or a software solution with clock dividers and who knows what.

It's no way better than a FIFO with independent clocks (but they of course must be close enough in frequency not to overfill or empty the FIFO buffer).
Low jitter clocks

It has not PLL, it's based on Tentlabs XO module (I believe).

I thought to use PLL to evenctually reclock I2S output.
  Reply With Quote
Old 19th April 2012, 05:23 PM   #406
diyAudio Member
 
iancanada's Avatar
 
Join Date: Dec 2009
Location: Toronto
Quote:
Originally Posted by 1audio View Post
I'm not sure how you arrive at the +6dB phase noise from the logic. I would like to know.

In the testing I have done recently I'm seeing more issues around deterministic noise that random phase noise. I would use reclocking D latches, possibly the Potato stuff and run them on an isolated supply. It only takes a little supply noise to modulate a clock in a gate, especially when we are looking at -120 to -150 dB.
Hi Demian, How are you doing?

The number came from a RF engineer who's job connected to oscillators design. He did measurement by those house price phase noise
analyzers. But he didn't mention the testing condition, as well as it's phase noise floor or close in phase noise.

Based on your measurement, how much additive jitter (converted to phase noise) will be introduced into a second generation clock by a
flip-flop ( take div by 2 for example)? and how about the different kind of flip-flops?

Did you mean a latch introduce less jitter than the flip-flop under the same condition?

Regards,
__________________
Ian GBV - I2S to PCM converter board & FIFO KIT
http://www.diyaudio.com/forums/group...ml#post3662743
  Reply With Quote
Old 20th April 2012, 01:54 AM   #407
diyAudio Member
 
iancanada's Avatar
 
Join Date: Dec 2009
Location: Toronto
Quote:
Originally Posted by andrea_mori View Post
Ian, friends,

a few years ago I bought an XO3 from Guido Tent, to use it to reclock CD PRO SPDIF, but if I'll feed directly FIFO buffer from CD PRO I2S data it become available for other applications.
Do you think that I can use XO3 as master clock in FIFO buffer?

Anyone has thought to use a PLL?

Andrea
Hi Andrea,
I'll upgrade the FIFO KIT supporting the left justified format before the second run.
I'm not familiar with XO3. If it is a good clock, you may feed it into the clock board of the FIFO KIT. Any re-clock before FIFO is useless. Because clock was isolated.
__________________
Ian GBV - I2S to PCM converter board & FIFO KIT
http://www.diyaudio.com/forums/group...ml#post3662743
  Reply With Quote
Old 20th April 2012, 07:35 AM   #408
vzs is offline vzs  Europe
diyAudio Member
 
Join Date: Dec 2005
Location: Cluj-Napoca, Romania
Quote:
Originally Posted by andrea_mori View Post
Low jitter clocks

It has not PLL, it's based on Tentlabs XO module (I believe).

I thought to use PLL to evenctually reclock I2S output.
My 2 cents on this as me neither knows Tent products well:
if I understand the XO3 is basically a clock module with a canned clock + a low noise regulator + some kind of spdif reclocking circuit - that's it.

Is your XO clock square shaped? if so it's an XO not VCXO.
What is the frequency of your XO clock? 11.2896 MHz or other?
Do you use this XO3 module with your CD-Pro? If yes - can you use your CD-Pro without this XO3 module?

Last edited by vzs; 20th April 2012 at 08:03 AM.
  Reply With Quote
Old 20th April 2012, 09:35 AM   #409
diyAudio Member
 
andrea_mori's Avatar
 
Join Date: Jan 2005
Location: Italy
Quote:
Originally Posted by vzs View Post
My 2 cents on this as me neither knows Tent products well:
if I understand the XO3 is basically a clock module with a canned clock + a low noise regulator + some kind of spdif reclocking circuit - that's it.

Is your XO clock square shaped? if so it's an XO not VCXO.
What is the frequency of your XO clock? 11.2896 MHz or other?
Do you use this XO3 module with your CD-Pro? If yes - can you use your CD-Pro without this XO3 module?
XO3 module replace CD PRO crystal oscillator and reclock spdif: to implement this module in CD PRO I have to remove crystal and relative caps, then I can take reclocked spdif from it.
I realize that I cannot use my XO3, clock frequency is 8.4672 Mhz compliant with CD PRO crystal clock, while I need 11.2896 for FIFO.
I think I can use CD PRO without this module because, as Ian said in a previous post, I feed FIFO buffer directly from CD PRO I2S data, so it was redundant.
  Reply With Quote
Old 20th April 2012, 09:48 AM   #410
vzs is offline vzs  Europe
diyAudio Member
 
Join Date: Dec 2005
Location: Cluj-Napoca, Romania
Quote:
Originally Posted by andrea_mori View Post
XO3 module replace CD PRO crystal oscillator and reclock spdif: to implement this module in CD PRO I have to remove crystal and relative caps, then I can take reclocked spdif from it.
I realize that I cannot use my XO3, clock frequency is 8.4672 Mhz compliant with CD PRO crystal clock, while I need 11.2896 for FIFO.
I think I can use CD PRO without this module because, as Ian said in a previous post, I feed FIFO buffer directly from CD PRO I2S data, so it was redundant.
If you did not removed the original crystal oscillator from your CD Pro this XO3 module is indeed useless.
I hoped you can use the XO clock from it, but not with this frequency.

I'm wondering what is the bit clock of the I2S at the CD PRO out
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
XMOS-based Asynchronous USB to I2S interface Lorien Digital Source 2043 17th April 2014 03:31 PM
exaU2I - Multi-Channel Asynchronous USB to I2S Interface exa065 exaDevices 1357 3rd March 2014 08:51 PM
DAC chip selection + I2S jitter questions drwho9437 Digital Line Level 2 26th July 2010 12:50 PM
Simple FIFO to I2S CPLD, for MCU players / reclocking KOON3876 Digital Line Level 21 19th September 2008 04:00 PM
asynchronous reclocking and low jitter clocks ash_dac Digital Source 3 8th February 2005 09:22 AM


New To Site? Need Help?

All times are GMT. The time now is 05:11 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2