Kwak Clock layout ??? - 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 24th February 2004, 07:39 AM   #1
Lyra is offline Lyra  Norway
diyAudio Member
 
Lyra's Avatar
 
Join Date: Nov 2003
Location: Norway
Question Kwak Clock layout ???

I am about to make a board (Eagle) for my KC7 implemantation....

What will be the "best" choice of:

-ground plane on component side
-ground plane on back-side
-both.....??


I am also implementing a 74HC125 logic to be able to drive the output when the board is placed close to the DAC, and the clock is feed backwards via 50ohm coax.
Should this logic, and corresponding transistor (2N4401) have it's own +5V supply, or could I just use +5V from the clock ???????


Lyra
  Reply With Quote
Old 24th February 2004, 02:15 PM   #2
diyAudio Member
 
Join Date: Dec 2001
Location: Eindhoven
Default Re: Kwak Clock layout ???

Quote:
Originally posted by Lyra
I am about to make a board (Eagle) for my KC7 implemantation....

What will be the "best" choice of:

-ground plane on component side
-ground plane on back-side
-both.....??


I am also implementing a 74HC125 logic to be able to drive the output when the board is placed close to the DAC, and the clock is feed backwards via 50ohm coax.
Should this logic, and corresponding transistor (2N4401) have it's own +5V supply, or could I just use +5V from the clock ???????


Lyra
Hi

You may look here for layout suggestions

http://members.chello.nl/~m.heijlige...decoupling.pdf

regards
__________________
Guido Tent
www.Tentlabs.com
  Reply With Quote
Old 24th February 2004, 05:36 PM   #3
Banned
 
Join Date: Dec 2001
Location: Zamboanga, City of Flowers, Mindanao
Send a message via Yahoo to Elso Kwak
Cool The Art of PCB Layout Design

Hi Lyra,
First remember electrons don't take sharp corners so avoid this situation by making rounded tracks.
http://www.audiotuning.de
(Click on Precision Clock)
To get the ground noise to an absolute minimum use a ground plane. See also:
http://www.national.com/rap/Story/0,1562,18,00.html
To quote from Audiocom:
The basic platform of Superclock II is its printed circuit board. This is formed as an extremely low impedance ground plane over which the components are placed. Very low impedance ground planes contribute to signal quality and are essential when handling radio frequency signals which are of exceptionally low distortion and phase jitter. The ground plane shields the radio circuits from the invisible capacitor formed when the board is mounted close to metalwork

Link:
http://www.1st-4-audio.com/control/n...asp?a=105&z=15
Even better go for a 4-layer board:
http://www.lcaudio.dk/com/intlcl.htm
Carbon composition resistors have the lowest inductance and should be used, preferentially in SMD format.
Also note that even a short trace on the PCB has inductance. So keep traces as short as possible, preferentially below one inch.
As for the power supply I quote from
http://www.trichordresearch.com/cdupgrades.html
Independent Power Supply available to isolate clock frequency noise from the rest of your CD player and also reduce other digital noise from the player entering the clock circuit.
Please see also:
http://www.net-audio.co.uk/clockpsu.html
Most authoritative paper:
http://www.analog.com/Analog_Root/st...nal_Sect10.pdf
(Page 17 and further)
Lyra I hope this answers your questions.

This entire post has been spell checked by Word in Windows.
  Reply With Quote
Old 24th February 2004, 05:55 PM   #4
diyAudio Member
 
Join Date: Dec 2001
Location: Eindhoven
Default Re: The Art of PCB Layout Design

Quote:
Originally posted by Elso Kwak
Hi Lyra,
First remember electrons don't take sharp corners so avoid this situation by making rounded tracks.
http://www.audiotuning.de/english/index.html
(Click on Precision Clock)
To get the ground noise to an absolute minimum use a ground plane. See also:
http://www.national.com/rap/Story/0,1562,18,00.html
To quote from Audiocom:
The basic platform of Superclock II is its printed circuit board. This is formed as an extremely low impedance ground plane over which the components are placed. Very low impedance ground planes contribute to signal quality and are essential when handling radio frequency signals which are of exceptionally low distortion and phase jitter. The ground plane shields the radio circuits from the invisible capacitor formed when the board is mounted close to metalwork

Link:
http://www.1st-4-audio.com/control/n...asp?a=105&z=15
Even better go for a 4-layer board:
http://www.lcaudio.dk/com/intlcl.htm
Carbon composition resistors have the lowest inductance and should be used, preferentially in SMD format.
Also note that even a short trace on the PCB has inductance. So keep traces as short as possible, preferentially below one inch.
As for the power supply I quote from
http://www.trichordresearch.com/cdupgrades.html
Independent Power Supply available to isolate clock frequency noise from the rest of your CD player and also reduce other digital noise from the player entering the clock circuit.
Please see also:
http://www.net-audio.co.uk/clockpsu.html
Most authoritative paper:
http://www.analog.com/Analog_Root/st...nal_Sect10.pdf
(Page 17 and further)
Lyra I hope this answers your questions.

This entire post has been spell checked by Word in Windows.

dear all,

At the freqs the round edgess are nonsense (if you know how the currents run and which parameters affect the routing of the current).

The impedance of the groundplane is not well understood by many designers, including the Audiocom guys (see above, and realise that currents run in loops).

A 4 layer board may be needed if the clock signal runs at bigger distances, like in our DAC design. I see no reason in a clock circuit, 2 layers are enough, at least that is what my measurements indicate.

Bottom line:
Control the currents through the groundplane, by making sure they travel through the shortest portion (i.e. place decoupling cap closest to the gnd pin of a chip)

Reduce RF currents by placing series impedances in supply and clock / data lines

Organise the floorplan in a logical way so the higheste frequencies / currents travel shortest way

NEVER interrupt the groundplane

By doing so, we achieved a virtual equipotential groundplane, now connect / decouple all component references (including their ground connections) to ground

succes
__________________
Guido Tent
www.Tentlabs.com
  Reply With Quote
Old 25th February 2004, 09:57 PM   #5
Lyra is offline Lyra  Norway
diyAudio Member
 
Lyra's Avatar
 
Join Date: Nov 2003
Location: Norway
This is my PCB-design as for now.
There might be some faults here and there. Keep in mind that this is my first layout using Eagle.....

BTW: the size of the board is aprox. 50x80 mm.

If there are something that look's not OK, please shout out

Lyra
Attached Images
File Type: jpg my_kc7_200.jpg (99.9 KB, 1589 views)
  Reply With Quote
Old 26th February 2004, 07:03 AM   #6
Electrons are yellow and more is better!
diyAudio Member
 
peranders's Avatar
 
Join Date: Apr 2002
Location: Göteborg, Sweden
Blog Entries: 4
The layout seems pretty OK to me but two things:

1 those 1 uF, why don't choose small 1 uF/63 V polyester? Maybe you chould go for 10-100 nF + 10 uF?

2 The 74HC IC hasn't got a decoupling cap close to pin Vcc.

Maybe you should consider SMD because this is better in almost all resepcts and it's not particulary hard to solder. Go for 0805 parts and SOT23 transistors.
__________________
/Per-Anders (my first name) or P-A as my friends call me
Super Regulator SSR03 Group buy
  Reply With Quote
Old 26th February 2004, 07:20 AM   #7
diyAudio Member
 
Join Date: Dec 2001
Location: Eindhoven
Quote:
Originally posted by Lyra
This is my PCB-design as for now.
There might be some faults here and there. Keep in mind that this is my first layout using Eagle.....

BTW: the size of the board is aprox. 50x80 mm.

If there are something that look's not OK, please shout out

Lyra

Hi Lyra

one remarks, as my response is limitted as I do not have the schematic at hand

You place the ferrite bead closer to the chips than the decoupling caps. I'd suggest to swop these, the cap should realy be close to the chips

succes
__________________
Guido Tent
www.Tentlabs.com
  Reply With Quote
Old 26th February 2004, 07:46 AM   #8
Electrons are yellow and more is better!
diyAudio Member
 
peranders's Avatar
 
Join Date: Apr 2002
Location: Göteborg, Sweden
Blog Entries: 4
When it comes to traces, always make them as short as possible, cut the corners also. Avoid 90 deg angles. Still I think you really should test SMD because smallness is very positive when it comes to digital circuits and oscillators. Not everything have to be SMD but resistors, < 100nF caps, transistors (regulators), IC's. The crystal can be holemounted.

Mask the groundplane in the skrew holes so the screw and/or the distance not make contact with the groundplane.

Look at the picture below.
Click the image to open in full size.
__________________
/Per-Anders (my first name) or P-A as my friends call me
Super Regulator SSR03 Group buy
  Reply With Quote
Old 28th February 2004, 02:13 AM   #9
Lyra is offline Lyra  Norway
diyAudio Member
 
Lyra's Avatar
 
Join Date: Nov 2003
Location: Norway
A (little) revised version......
Attached Images
File Type: jpg 200.jpg (99.8 KB, 1250 views)
  Reply With Quote
Old 28th February 2004, 02:19 AM   #10
Lyra is offline Lyra  Norway
diyAudio Member
 
Lyra's Avatar
 
Join Date: Nov 2003
Location: Norway
....and in more real size....
Attached Images
File Type: jpg 600.jpg (18.5 KB, 1258 views)
  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
My Kwak Clock 7 zygibajt Digital Source 12 28th November 2010 02:37 PM
49.152 MHz Kwak clock okkyn Digital Source 0 10th July 2007 02:53 AM
kwak clock trouble pjoasti Digital Source 1 20th February 2007 08:01 AM
Kwak clock versus Tent clock rbroer Digital Source 22 21st September 2003 01:20 PM
help with Kwak-clock jarthel Digital Source 5 4th May 2002 04:16 PM


New To Site? Need Help?

All times are GMT. The time now is 06:54 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