No reclocking DAC. Are they fine? - diyAudio
Go Back   Home > Forums > Source & Line > Digital Source

Digital Source Digital Players and Recorders: CD , SACD , Tape, Memory Card, 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 26th July 2005, 12:27 PM   #1
beppe61 is offline beppe61  Italy
diyAudio Member
 
Join Date: Feb 2005
Location: torino
Default No reclocking DAC. Are they fine?

Dear Sirs,


I read somewhere that some external dacs don't reclock the incoming digital signal ( they are slave to the transport).
Someone say that this could give a more natural sounding dac.
I would like to hear some experts' opinion.

Thank you very much indeed.

Kind regards,

beppe61
  Reply With Quote
Old 13th September 2005, 06:09 PM   #2
beppe61 is offline beppe61  Italy
diyAudio Member
 
Join Date: Feb 2005
Location: torino
Dear Sirs,


I would like to hear some comments about the reclocking process.
What is your experience?
I have an external dac (Behringer SRC 2496) and prefer the sound without reclocking (i.e. using the clock embedded in the incoming SPDIF digital signal).
It seems indeed more natural and less digital to me.

Kind regards,

beppe61
ITALY
  Reply With Quote
Old 13th September 2005, 07:08 PM   #3
diyAudio Member
 
Join Date: Jul 2005
Location: Timisoara
If the source has a stable clock and low jitter on output, then it's no problem sync'ing on it.

If not, better get a dac with buffer and internal clock.

The idea is to get the bits to the dac at the exact time they are supposed to, no matter which method you use to accomplish this.
  Reply With Quote
Old 13th September 2005, 07:19 PM   #4
diyAudio Member
 
Join Date: Dec 2001
Location: Eindhoven
Quote:
Originally posted by danb1974
If the source has a stable clock and low jitter on output, then it's no problem sync'ing on it.

If not, better get a dac with buffer and internal clock.

The idea is to get the bits to the dac at the exact time they are supposed to, no matter which method you use to accomplish this.

It IS a problem because the way SPDIF is coded, much jitter is induced in the interface, so a wide bandwidth PLL at the DAC is a disaster, no matter how clean the drive is.

The conversion process is of utmost importance as jitter induces distortion in the DAC, hence the DAC clock should be of lowest jitter possible. In addition all signals entering the DAC chip should be reclocked as to reduce on-chip crosstalk.

best
__________________
Guido Tent
www.Tentlabs.com
  Reply With Quote
Old 14th September 2005, 01:40 AM   #5
diyAudio Member
 
Join Date: Jul 2004
Location: MD, USA
Default Re: No reclocking DAC. Are they fine?

Quote:
Originally posted by beppe61
I read somewhere that some external dacs don't reclock the incoming digital signal ( they are slave to the transport).
Actually, most of them


Quote:
Originally posted by beppe61
I would like to hear some comments about the reclocking process.
What is your experience?
What I got implementing synchronous reclocking:
1) Resolution enhancement.
2) My computer 10m away and CD transport sound identically.
3) Digital cables sound the same
  Reply With Quote
Old 14th September 2005, 01:52 AM   #6
EC8010 is offline EC8010  United Kingdom
diyAudio Moderator Emeritus
 
EC8010's Avatar
 
Join Date: Jan 2003
Location: Near London. UK
Default Re: Re: No reclocking DAC. Are they fine?

Quote:
Originally posted by stolbovoy
3) Digital cables sound the same
I thought that, then had to lengthen a digital (S/PDIF) cable, and it didn't sound as good. As an engineer, I thought, "It's only 1s and 0s, so why the difference?" So I looked at the characteristic impedance of the cable and its termination. Whoops. The connection was generating jitter because of the Manchester coding violation alluded to by Guido plus mismatched impedances. What you need is a proper cable with guaranteed matched source and desitination impedances; then they'll all sound the same.
__________________
The loudspeaker: The only commercial Hi-Fi item where a disproportionate part of the budget isn't spent on the box. And the one where it would make a difference...
  Reply With Quote
Old 14th September 2005, 02:15 AM   #7
diyAudio Member
 
Join Date: Jul 2004
Location: MD, USA
Default Re: Re: Re: No reclocking DAC. Are they fine?

Quote:
The connection was generating jitter because of the Manchester coding violation alluded to by Guido plus mismatched impedances.
Typically jitter does nothing with Manchester encoding violation. One will receive the same data as sent with almost any junk cable/termination at short distances. Problem is in a clock recovery.
  Reply With Quote
Old 14th September 2005, 02:26 AM   #8
Banned
 
Join Date: Feb 2002
Location: As far from the NOSsers as possible
Try using a longer cable, with proper terminations. Then tell me that you don't hear a difference.

Jocko
  Reply With Quote
Old 14th September 2005, 07:06 AM   #9
beppe61 is offline beppe61  Italy
diyAudio Member
 
Join Date: Feb 2005
Location: torino
Dear Sirs,


I want to thank you all for your extremely kind and very valuable reply.
For the first time I get very valuable responses to my doubts.
Sadly the task to connect adequately a transport and a dac seems very difficult to make.
Actually I hoped it was simpler.
Anyway you have been very helpful for me understanding something more of the phenomena.

Thank you very much sincerely.

Kind regards,

beppe61
  Reply With Quote
Old 14th September 2005, 07:26 AM   #10
bocka is offline bocka  Germany
diyAudio Member
 
Join Date: Jul 2003
Location: Hannover
Quote:
"It's only 1s and 0s, so why the difference?"
Every bandlimited system with non static input data signals induces jitter, because the non harmonic part of the differential equation is not zero or better said not equal for every time interval. Of course there are other differences like signal dispersion, unstable reference points by noisy power supplies, ground bouncing and probably some more.

Timing also in the digital domain is an analog phenomenon as there are no electrical '0's and '1's but only (analog) signal levels.
  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
Decoder output: how jittery, worth reclocking? And "double" reclocking hollowman Digital Source 0 17th July 2009 01:39 PM
F3 fine tuning ZUM911 Pass Labs 5 31st January 2008 09:14 PM
Need clue. R speaker static when low volume, fine loud, headphones fine. . . Help? danielwritesbac Solid State 4 30th December 2007 03:29 PM
Will this ckt work fine? rejithcv Power Supplies 42 30th November 2006 07:04 AM
U.D.A. A very fine recording emperor Everything Else 4 12th August 2002 04:59 PM


New To Site? Need Help?

All times are GMT. The time now is 01:39 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