Splitting ground - diyAudio
Go Back   Home > Forums > General Interest > Everything Else

Everything Else Anything related to audio / video / electronics etc) BUT remember- we have many new forums where your thread may now fit! .... Parts, Equipment & Tools, Construction Tips, Software Tools......

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 16th August 2002, 08:05 AM   #1
Vivek is offline Vivek  India
diyAudio Member
 
Join Date: Nov 2000
Location: Bangalore, India
Default Splitting ground

Hi,
How does one split the signal ground and the power ground? Don't they all go to one point eventually. Thanks for any comment.

Vivek
  Reply With Quote
Old 16th August 2002, 02:10 PM   #2
diyAudio Member
 
mrfeedback's Avatar
 
Join Date: Feb 2002
Location: Perth, Australia.
Default Looping and Jacking.

Hi Vuvek,
For correct earth referencing, the input, power supply and speaker grounds should return to a single point (the power supply central ground point) from different directions, being careful to minimise each of these circuit loop areas.
If you have different circuit stages grounded on a common line, the resultant earth jacking can cause additive or subtractive valid signal production - this can cause a transient limiting/foldback characteristic, or a flaring/blapping characteristic according to stage earthing order and behaviour.
Intelligent placing/ordering of these interactive earths can give a desirable envelope response, and give voice to an amplifier system.

Eric.
  Reply With Quote
Old 16th August 2002, 10:28 PM   #3
diyAudio Member
 
MRehorst's Avatar
 
Join Date: May 2002
Default Re: Looping and Jacking.

Quote:
Originally posted by mrfeedback
<snip>
If you have different circuit stages grounded on a common line, the resultant earth jacking can cause additive or subtractive valid signal production - this can cause a transient limiting/foldback characteristic, or a flaring/blapping characteristic according to stage earthing order and behaviour.
Intelligent placing/ordering of these interactive earths can give a desirable envelope response, and give voice to an amplifier system.

Eric.
Uh, can you translate any of that to English?



Cheers!

MR
  Reply With Quote
Old 16th August 2002, 11:13 PM   #4
diyAudio Member
 
NU_NRG's Avatar
 
Join Date: Dec 2001
Location: Quebec, CANADA
Send a message via ICQ to NU_NRG
Default hummm

How about - Don't let High current from Speaker Output flow through the same ground ground path used by the control circuitery.

Simply use 2 different ground track on your pcb and connect them via 2 different wire to the capacitor grounding point. One ground for all the High Current and another for the input and signal transistors.

Clearer?


-Simon
  Reply With Quote
Old 17th August 2002, 01:26 AM   #5
diyAudio Member
 
mrfeedback's Avatar
 
Join Date: Feb 2002
Location: Perth, Australia.
Default Voicing in Strine

Aussie English translation - putting input ground and speaker ground on the same line can cause useful or destructive feedback - not enough to cause oscillation, but enough to change the envelope response of the amplifier system.
This can (and does) give voicing.

Eric.
  Reply With Quote
Old 17th August 2002, 02:10 AM   #6
diyAudio Member
 
Join Date: Jan 2002
Location: Cleveland ohio
What do you mean by voicing??
  Reply With Quote
Old 17th August 2002, 02:22 AM   #7
diyAudio Member
 
mrfeedback's Avatar
 
Join Date: Feb 2002
Location: Perth, Australia.
Subtle tone control (frequency response non perfect flatness and power evelope behaviours) caused by feedbacks.
These give a signature sound to a construction, in addition to the circuit design characteristics.

Eric.
  Reply With Quote
Old 17th August 2002, 02:32 AM   #8
diyAudio Member
 
MRehorst's Avatar
 
Join Date: May 2002
Are you actually suggesting that ground loops are intentionally added to amplifier designs to modify the frequency response and "envelope" response (whatever that is)?

MR

  Reply With Quote
Old 17th August 2002, 02:46 AM   #9
Vivek is offline Vivek  India
diyAudio Member
 
Join Date: Nov 2000
Location: Bangalore, India
Hi,
Thanks to all for your comments but I still do not get it.

"Simply use 2 different ground track on your pcb and connect them via 2 different wire to the capacitor grounding point."

Simon,
Are you saying that the input and driver trans have to be grounded to one point and the input and output terminals will use a different ground track and the two are connected?

Vivek
  Reply With Quote
Old 17th August 2002, 09:29 AM   #10
diyAudio Member
 
mrfeedback's Avatar
 
Join Date: Feb 2002
Location: Perth, Australia.
Hi MR,
In years of servicing audio gear I have seen all sorts of dumb wiring and pcb layout arrangements.
This includes doubtful power supply, preamp and power amp supply and grounding layouts, and other errors like taking NFB from an invalid (wrong) point.
I think it is not so much intentional as lacking of knowledge on the designers part.
Some munufacturers do however very deliberately adhere to star grounding of all stages, particularly in modern higher quality shelf systems.
A common error is an inadequate size pcb trace ground common connecting the two main filter caps.
Other errors include grounding stages to the speaker earth return traces.
A close look at the layout and intelligent rerouting and/or beefing up of some pcb traces can yield worthwhile improvement.
Bypassing of main filter caps with additional SMPS electros of around 10% of the main caps is usually a wortwhile improvement also.


Vivek,
Star grounding means that you have a substantial copper area connecting the two main filter caps, and this is the system earth reference to which all stages and input and output connectors are individually connected.
Eric.
  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
Should I directly connect my signal ground to chassis ground? Bricolo Solid State 4 18th March 2014 09:42 PM
Parallel LM3886, input ground, power ground, safety resistor and oscillations. markiemrboo Chip Amps 5 9th August 2007 03:50 PM
DC filament ground and high voltage ground mikeyho Tubes / Valves 0 15th September 2005 05:52 PM
Chassis Ground = Circuit Ground --&gt; Problems? rhildenbrand Pass Labs 5 23rd April 2004 01:08 AM
does connecting mains ground with circuit ground create a ground loop? jarthel Everything Else 0 25th June 2003 12:55 PM


New To Site? Need Help?

All times are GMT. The time now is 06:11 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