Is this DC offset problem. - diyAudio
Go Back   Home > Forums > Amplifiers > Chip Amps

Chip Amps Amplifiers based on integrated circuits

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 22nd December 2004, 02:38 PM   #1
rs1026 is offline rs1026  India
diyAudio Member
 
Join Date: Jul 2004
Location: Bangalore
Default Is this DC offset problem.

Whenever i switch on my lm3886 based gainclone I observe that the papercone of woofer moves forward and then goes back.This is observed even when I switch of the amp.However instead of switching on the amp if I slowly push the powercord into the mains socket I dont observe this movement of the cone.

Is this a DC offset problem?Is this movement common in gain alone amps?Will this movement damage the drivers in the long run?
  Reply With Quote
Old 22nd December 2004, 04:29 PM   #2
Stocker is offline Stocker  United States
diyAudio Member
 
Join Date: Dec 2003
Location: Austin
This is turn-on thump. solutions are available, do some searching. Usually it is only annoying. If you measure the voltage at your speaker terminals you will be able to tell if you have excessive DC offset.
__________________
Jesus loves you.
  Reply With Quote
Old 22nd December 2004, 09:52 PM   #3
diyAudio Member
 
thomas997's Avatar
 
Join Date: Feb 2004
Location: Vancouver
Do you have an X type cap across your switch? That might help..


If there is a lot of DC offset the cone will move in a direction, and stay in that direction..

As stocker said, get out the multimeter and measure mV at terminals.
  Reply With Quote
Old 22nd December 2004, 10:08 PM   #4
diyAudio Member
 
Join Date: Oct 2004
Default Is this DC offset problem

Thomas997 What do you mean X type cap across yours switch
  Reply With Quote
Old 24th December 2004, 12:02 AM   #5
diyAudio Member
 
thomas997's Avatar
 
Join Date: Feb 2004
Location: Vancouver
Default Re: Is this DC offset problem

Quote:
Originally posted by jaudio
Thomas997 What do you mean X type cap across yours switch

Something similar to what is shown on this site:

http://www.sector101.fsnet.co.uk/cyb...inside/switch/

Across the mains switch.
  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
offset problem intense-tavda Solid State 6 22nd June 2009 08:24 AM
DC offset problem mravlcax Chip Amps 21 30th April 2008 10:08 AM
Another Offset problem... rtate Solid State 6 19th March 2008 11:03 AM
DC-offset problem Bootstrapper Solid State 12 6th October 2007 08:25 AM
A40 offset problem? stickleda Pass Labs 8 1st May 2005 12:56 AM


New To Site? Need Help?

All times are GMT. The time now is 08:07 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