Discrete Low Jitter Clock GB - Page 13 - diyAudio
Go Back   Home > Forums > Commercial Sector > Group Buys

Group Buys Members group buys

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 27th February 2012, 07:05 AM   #121
amc184 is offline amc184  New Zealand
diyAudio Member
 
amc184's Avatar
 
Join Date: May 2007
Location: Christchurch
No, you can't skip the comparator if you want a clock output that is suitable as a master clock for a CD player (the purpose of the project). You could replace its functionality with discrete components, but it's not something I'd recommend.
__________________
Inside Classic Audio, my blog on repairs, modifications and anything else to do with audio.
  Reply With Quote
Old 27th February 2012, 07:14 AM   #122
diyAudio Member
 
Join Date: Jan 2006
Location: Las Vegas
any more pcb's available?
  Reply With Quote
Old 27th February 2012, 07:17 AM   #123
amc184 is offline amc184  New Zealand
diyAudio Member
 
amc184's Avatar
 
Join Date: May 2007
Location: Christchurch
Yes, I've still got a couple of PCBs spare, PM me your details.
__________________
Inside Classic Audio, my blog on repairs, modifications and anything else to do with audio.
  Reply With Quote
Old 17th April 2012, 04:00 PM   #124
diyAudio Member
 
andrea_mori's Avatar
 
Join Date: Jan 2005
Location: Italy
Any pcb's available?
  Reply With Quote
Old 17th April 2012, 04:07 PM   #125
diyAudio Member
 
Join Date: Nov 2006
Location: Lyon
Hi Anton
I've finished one LJC module today.
Measuring 4.93V on pin1 of AD8561 vs 5V.
Is it Ok ?
What kind of wire do you use ?
Thanks
  Reply With Quote
Old 18th April 2012, 10:25 AM   #126
roender is offline roender  Romania
diyAudio Member
 
roender's Avatar
 
Join Date: Sep 2006
Did someone measured the phase noise in frequency domain for this clock?
  Reply With Quote
Old 19th May 2012, 09:16 AM   #127
diyAudio Member
 
Join Date: Oct 2009
Location: Brunei
Quote:
Originally Posted by amc184 View Post
No, you can't skip the comparator if you want a clock output that is suitable as a master clock for a CD player (the purpose of the project). You could replace its functionality with discrete components, but it's not something I'd recommend.
Can you please elaborate?
What's the function of the comparator? Purely buffering?

thanks
  Reply With Quote
Old 19th May 2012, 09:55 AM   #128
amc184 is offline amc184  New Zealand
diyAudio Member
 
amc184's Avatar
 
Join Date: May 2007
Location: Christchurch
@korben69: That's fine, well within margin. The output connector pattern suits SMA / SMB / SMC connectors, so usually you'd use something like RG316. The cabling isn't critical over very short distances, and the clock should be positioned very close to the point where it is to be used so that the transmission distance is kept very short. The clock isn't designed to drive a transmission line. Sorry about the late reply, I hope the answer is still useful.

@roender: No, I've already answered this question.

@studiostevus: The comparator is absolutely essential, it can't be omitted. Its function is to transform the two out of phase sinusoidal signals from the oscillator into a single squarewave. It's not merely a buffer.
__________________
Inside Classic Audio, my blog on repairs, modifications and anything else to do with audio.
  Reply With Quote
Old 19th May 2012, 10:46 AM   #129
diyAudio Member
 
Join Date: Oct 2009
Location: Brunei
Thanks for explaining.

Any idea about the effect of the comparator on jitter/phase noise...? The data sheet mentions a 7ns propagation delay, no mention of jitter (15ps typical i read somewhere). In any case, i believe that any psu noise to the comparator will result in phase noise...

Worth mentioning is also that not all devices require a square waveform to trigger. Have you tried to use it without?
__________________
--------
TDA1541a-S2 / 6072a / MediaplayerDac -- Michell Gyrodec -- Aikido Preamp -- Pass F5 -- Audio Physic Tempo 2SE -- Yamamura Cabling
  Reply With Quote
Old 19th May 2012, 02:28 PM   #130
amc184 is offline amc184  New Zealand
diyAudio Member
 
amc184's Avatar
 
Join Date: May 2007
Location: Christchurch
The comparator will add some phase noise, but it's not separable from the rest of the design. However, what it adds is by far outweighed by what it does by providing a squared output and the cancellation of common mode noise from the oscillator.

Quote:
In any case, i believe that any psu noise to the comparator will result in phase noise...
Did you note that the comparator runs off a separate regulated supply to the oscillator?

Quote:
Worth mentioning is also that not all devices require a square waveform to trigger. Have you tried to use it without?
As long as the waveform is of adequate voltage, almost any wave shape (triangle, sine etc) will work with almost any device. However, one of the significant causes of jitter is noise in the transition voltage of the receiving device. The jitter caused by this is proportional to the slope of the waveform about the transition, the steeper the slope the less jitter. Why would you want to use anything but a square wave?
__________________
Inside Classic Audio, my blog on repairs, modifications and anything else to do with audio.
  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
opamp / low jitter clock for maranatz sweepy DIY HiFi Supply 1 5th April 2011 01:48 AM
FS: Low Jitter Clock PCBs amc184 Swap Meet 6 20th June 2010 07:00 AM
Is this cristal clock schematic would have a low jitter ? gaetan8888 Digital Line Level 8 20th May 2010 03:13 PM
low jitter clock help needed atcgreg Digital Line Level 10 9th June 2009 07:58 AM
Another clock idea for low jitter Bernhard Digital Source 7 29th October 2004 05:05 PM


New To Site? Need Help?

All times are GMT. The time now is 08:21 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