Marsh headphone amp from Linear Audio - Page 31 - diyAudio
Go Back   Home > Forums > Amplifiers > Headphone Systems

Headphone Systems Everything to do with Headphones

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 June 2012, 06:20 PM   #301
RNMarsh is offline RNMarsh  United States
diyAudio Member
 
RNMarsh's Avatar
 
Join Date: May 2012
Location: 2457 Cascade Trail; Cool, CA. 95614
Quote:
Originally Posted by john curl View Post
Go for it, Dick!
Hi John! I see you are back (?) in Berkeley land. I have been up in the foothills of the Sierra's - a stones throw from Nelson Pass - for the past 15 years. Cool, CA. Its a nice drive... come up and visit me.

Last edited by RNMarsh; 20th June 2012 at 06:22 PM.
  Reply With Quote
Old 20th June 2012, 08:19 PM   #302
RNMarsh is offline RNMarsh  United States
diyAudio Member
 
RNMarsh's Avatar
 
Join Date: May 2012
Location: 2457 Cascade Trail; Cool, CA. 95614
Default seperating power ground from signal ground on the pcb

Here is an example of what I generally do -- I use two pcb ground plans: I have a seperate power ground on opposite pcb sides of +/- traces that form a strip-line for low z distribution. It never goes over signal traces and has a seperate path to the power source ground point.
The signal shield/ground is only over the signal area/wiring. Never crosses over power wires/traces or signal ground plane areas.
Separated power and signal returns are an important part of the high-end pcb design. This keeps power filtered transient currents/ripple/rfi et al out of the signal paths (via common). Result? Greater sonic clarity and seperation. -RNM

Last edited by RNMarsh; 20th June 2012 at 08:33 PM. Reason: PCB grounds - use seperate paths
  Reply With Quote
Old 21st June 2012, 02:15 AM   #303
RNMarsh is offline RNMarsh  United States
diyAudio Member
 
RNMarsh's Avatar
 
Join Date: May 2012
Location: 2457 Cascade Trail; Cool, CA. 95614
Default Dual grnd planes

example using old pcb circuit - green color are the two seperate ground planes: signal and power.
right side is power and left or center is signal. Traces are above the ground planes in red. -RNM
Attached Images
File Type: jpg pcb dual grnd plane.jpg (330.0 KB, 627 views)

Last edited by RNMarsh; 21st June 2012 at 02:29 AM.
  Reply With Quote
Old 21st June 2012, 03:42 AM   #304
sonidos is offline sonidos  United States
Libertador de la Música
diyAudio Member
 
sonidos's Avatar
 
Join Date: Jul 2007
Location: Round Rock, TX
@ RNMarsh

Things just got a lot clearer in my head thanks to the last 2 posts. Beautiful.
  Reply With Quote
Old 21st June 2012, 12:08 PM   #305
Unomas is offline Unomas  Spain
diyAudio Member
 
Join Date: Feb 2008
Thanks Mr. Marsh, that is a great (though not a new one as you say!) rule to start dealing with ground. In my old days of circuits designer I had to deal with some very tough ground issues and keeping both power and signal GNDs well isolated and controlled in PCB routing was very helpful indeed. The magic rule is to avoid power ground current to interfere with signal ground as much as possible.

Another good rule is forgetting about the "magic" theoretical GND that could deal with everything with zero impedance! Always try imagine current paths in GND (following the least impedance route) to come back to source point and, in case you observe a conflict and/or interference with weak signals, try other route to avoid it.

Well we could continue with this issue for a long time but I think is better to point out that there are some very helpful resources for those interested. A good starting point may be:

- "Staying Well Grounded" H. Zumbahlen - Analog Dialog 2012-06 (Analog Devices Inc)
Here you can find a good deal of information and, what is even more important, a very helpful list of references on the Grounding subject.

Javier
  Reply With Quote
Old 21st June 2012, 12:28 PM   #306
diyAudio Member
 
jackinnj's Avatar
 
Join Date: Apr 2002
Location: Llanddewi Brefi, NJ
One ground plane -- the Node "0" routing is shown in cyan and can be attached to the ground plane (which would make the copper pour "cyan").

Click the image to open in full size.

I have a couple of prototype boards to dispense of, free for the shipping -- all soldered up etc., etc. Anyone interested drop me a PM.
  Reply With Quote
Old 22nd June 2012, 06:33 AM   #307
rjm is offline rjm  Japan
Richard Murdey
diyAudio Member
 
rjm's Avatar
 
Join Date: May 2004
Location: Kyoto
Blog Entries: 98
Quote:
Originally Posted by RNMarsh View Post
example using old pcb circuit - green color are the two seperate ground planes: signal and power.
right side is power and left or center is signal. Traces are above the ground planes in red. -RNM
Where does the signal ground plane connect to the power ground plane?
__________________
RJM Audio (phonoclone.com / G+)
  Reply With Quote
Old 22nd June 2012, 09:41 PM   #308
RNMarsh is offline RNMarsh  United States
diyAudio Member
 
RNMarsh's Avatar
 
Join Date: May 2012
Location: 2457 Cascade Trail; Cool, CA. 95614
At the power supply common - usually the center tap of the power transformer. You use a seperate wire for that. Then, both power ground and signal ground planes/shields go back to same point.
  Reply With Quote
Old 22nd June 2012, 10:07 PM   #309
RNMarsh is offline RNMarsh  United States
diyAudio Member
 
RNMarsh's Avatar
 
Join Date: May 2012
Location: 2457 Cascade Trail; Cool, CA. 95614
Default seperate ground paths

Like this shown -->
Attached Images
File Type: jpg seperate grounding.jpg (398.7 KB, 469 views)

Last edited by RNMarsh; 22nd June 2012 at 10:10 PM.
  Reply With Quote
Old 22nd June 2012, 10:34 PM   #310
diyAudio Member
 
jackinnj's Avatar
 
Join Date: Apr 2002
Location: Llanddewi Brefi, NJ
Anything objectionable about this:

Click the image to open in full size.
  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
FS: Meier Audio Corda Headphone Amp jtwrace Swap Meet 5 29th February 2012 11:34 AM
Histoically significant - Phase Linear audio pre-amp bobcul Swap Meet 0 21st February 2012 08:16 PM
Headphone amp with mixed-in telephone audio krfjr1965 Solid State 3 10th March 2010 03:50 PM


New To Site? Need Help?

All times are GMT. The time now is 09:17 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