Asynchronous I2S FIFO project, an ultimate weapon to fight the jitter - Page 42 - diyAudio
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 20th April 2012, 09:54 AM   #411
diyAudio Member
 
andrea_mori's Avatar
 
Join Date: Jan 2005
Location: Italy
Quote:
Originally Posted by iancanada View Post
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.
Hi Ian,

thanks for upgrade. Do you implement this feature in a new bord?

About PLL reclocking I meant after FIFO, before DAC or DF.
  Reply With Quote
Old 20th April 2012, 10:15 AM   #412
vzs is offline vzs  Europe
diyAudio Member
 
Join Date: Dec 2005
Location: Cluj-Napoca, Romania
Hi Ian,
Regarding Andrea's CDPro - FIFO issue: if I understand well CDPro uses SAA7372 or SAA7374, both output I2S in 48bit format not 64, thus the output SCK according to the manual is 2.1168MHz
Can the FIFO handle this? - if not he can still use the spdif output of CDPro with your spdif board then the FIFO but not direct I2S
Thanks,
Zsolt

Last edited by vzs; 20th April 2012 at 10:21 AM.
  Reply With Quote
Old 20th April 2012, 10:15 AM   #413
diyAudio Member
 
wktk_smile's Avatar
 
Join Date: Dec 2009
Location: Kyoto
Hi, Ian

Your FIFO+reclocker combined with Sabre dac is really impressive, especially when synchronous mode between the dac and reclocker.

When I first fired up SDTrans384 - FIFO plus reclocker( U1 is replaced with NDK NZ2520SD ) - Buffalo2 setup, I immediately noticed this obviously outperforms SDTrans384 - Buffalo2 combo.
Side by side comparison was never needed.

Now I can hear more low-level informations more easily and feel as if near the everything some more precise - bass are better controlled, less harsh Hi, and so on.

Really good job indeed, and I'm glad to see you still seek more improvement and versatility...


Thanks!
  Reply With Quote
Old 20th April 2012, 10:22 AM   #414
diyAudio Member
 
wktk_smile's Avatar
 
Join Date: Dec 2009
Location: Kyoto
DSD support and capability of faster MCLK output would be nice if the board revisions were
planned in the future
  Reply With Quote
Old 20th April 2012, 10:36 AM   #415
diyAudio Member
 
andrea_mori's Avatar
 
Join Date: Jan 2005
Location: Italy
Quote:
Originally Posted by vzs View Post
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
I think 33.8688 Mhz.
It use SAA7324
(http://www.daisy-laser.com/products/.../SAA7324_2.pdf).
  Reply With Quote
Old 20th April 2012, 10:51 AM   #416
vzs is offline vzs  Europe
diyAudio Member
 
Join Date: Dec 2005
Location: Cluj-Napoca, Romania
Quote:
Originally Posted by andrea_mori View Post
I think 33.8688 Mhz.
It use SAA7324
(http://www.daisy-laser.com/products/.../SAA7324_2.pdf).
Same as for the others - see page 18: for 1xfs the SCLK = 2.1168MHz or multiples of this so 48bit I2S frame.
Let's wait to see what Ian says about this. In worst case you use the spdif out of CDPro to spdif board of FIFO.
  Reply With Quote
Old 20th April 2012, 10:56 AM   #417
diyAudio Member
 
soundcheck's Avatar
 
Join Date: Mar 2005
Location: D
Hi guys.

Interesting project.

Let me ask you a question.

Pretty much all computer audio interfaces suffer of noise, jitter, intermodulations, drifts, you name it, fed from the PC or transport via USB, SPDIF, you name it.

Slightest optimizations (HW/SW) on the transport side usually have an impact on the sound. (See my Touch Toolbox effects, audiophile SW player effects, .wav vs. .flac., asf. asf.

I'm not aware of any audiointerface which wouldn't respond to those upstream optimizations.

Now. If for example I'd connect a Wave-IO XMOS USB interface (you might have followed discussions over here at DIY-audio) and the reclocker,
do you guys think, the impact of the upstream mess would be gone -- as long words and bits are the same????

Thx for your feedback.

Cheers
  Reply With Quote
Old 20th April 2012, 12:31 PM   #418
diyAudio Member
 
iancanada's Avatar
 
Join Date: Dec 2009
Location: Toronto
Quote:
Originally Posted by vzs View Post
Hi Ian,
Regarding Andrea's CDPro - FIFO issue: if I understand well CDPro uses SAA7372 or SAA7374, both output I2S in 48bit format not 64, thus the output SCK according to the manual is 2.1168MHz
Can the FIFO handle this? - if not he can still use the spdif output of CDPro with your spdif board then the FIFO but not direct I2S
Thanks,
Zsolt
Hi Vzs,

My FIFO is 100% compatible with I2S standard. So, it doesn't matter how many sck per word or sck frequency. Any word length between true 16bit to true 32bit is working. Thank you so much for noticing me about that.

For Andrea's project, if that XO3 is just for upgrading CDPro, then with the FIFO attached, I don't think he need it. He just need connect the I2S output directly from the CDPro into the FIFO.
__________________
Ian GBV - I2S to PCM converter board & FIFO KIT
http://www.diyaudio.com/forums/group...ml#post3662743
  Reply With Quote
Old 20th April 2012, 12:37 PM   #419
diyAudio Member
 
andrea_mori's Avatar
 
Join Date: Jan 2005
Location: Italy
Quote:
Originally Posted by vzs View Post
Same as for the others - see page 18: for 1xfs the SCLK = 2.1168MHz or multiples of this so 48bit I2S frame.
Let's wait to see what Ian says about this. In worst case you use the spdif out of CDPro to spdif board of FIFO.
I've seen the datasheet, 2.1168 x n.
Spdif in not the best solution, I2S is definitely a cleaner solution, but if no other solution I'll use spdif.

Well, I'm waiting for Ian impression about this.
  Reply With Quote
Old 20th April 2012, 12:59 PM   #420
diyAudio Member
 
andrea_mori's Avatar
 
Join Date: Jan 2005
Location: Italy
Quote:
Originally Posted by iancanada View Post
Hi Vzs,

My FIFO is 100% compatible with I2S standard. So, it doesn't matter how many sck per word or sck frequency. Any word length between true 16bit to true 32bit is working. Thank you so much for noticing me about that.

For Andrea's project, if that XO3 is just for upgrading CDPro, then with the FIFO attached, I don't think he need it. He just need connect the I2S output directly from the CDPro into the FIFO.
Ian

Good news for me!
at this point is missing only to feed directly NPC, so my project will be complete.

Thanks
  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 2126 20th August 2014 02:09 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 06:26 AM.


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