Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Class D Switching Power Amplifiers and Power D/A conversion

TPA3116D2 Amp
TPA3116D2 Amp
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 15th November 2018, 09:18 PM   #10741
voltwide is offline voltwide  Ireland
diyAudio Member
 
Join Date: Jan 2010
if you measure the output at the speaker terminals behind the LC-output filter there is little switching signal remaining so a regular DVM should do.

And obviously your DVM works correct at the working channel.

One output is hi, the other low. So I would assume there is some DC-error signal at one or both inputs.

Perhaps a faulty coupling cap. Are there MLCC coupling caps? If so, replace this crap by film caps.

Last edited by voltwide; 15th November 2018 at 09:26 PM.
  Reply With Quote
Old 15th November 2018, 09:29 PM   #10742
FauxFrench is offline FauxFrench  France
diyAudio Member
 
Join Date: Dec 2017
Location: The mountains, calm and quiet.
Quote:
Originally Posted by voltwide View Post
if you measure the output at the speaker terminals behind the LC-output filter there is little switching signal remaining so a regular DVM should do.

The problem of using the ordinary LC output filter is that a load is needed to dampen the filter and avoid over-voltage. As the outputs appear to have an important DC component between them, the outputs will be overloaded by the DC current and the undisturbed values cannot be measured.
  Reply With Quote
Old 15th November 2018, 09:40 PM   #10743
voltwide is offline voltwide  Ireland
diyAudio Member
 
Join Date: Jan 2010
Quote:
Originally Posted by FauxFrench View Post
The problem of using the ordinary LC output filter is that a load is needed to dampen the filter and avoid over-voltage. As the outputs appear to have an important DC component between them, the outputs will be overloaded by the DC current and the undisturbed values cannot be measured.
If this was the problem, an 5~10R dummy resistor should do the trick.
In case of DC overheating the resistor, put in series a film cap 1uF - now you have a damping snubber.
Anyway, the symptoms described lead me to a DC input error.

Last edited by voltwide; 15th November 2018 at 09:43 PM.
  Reply With Quote
Old 15th November 2018, 09:53 PM   #10744
FauxFrench is offline FauxFrench  France
diyAudio Member
 
Join Date: Dec 2017
Location: The mountains, calm and quiet.
Quote:
Originally Posted by voltwide View Post
If this was the problem, an 5~10R dummy resistor should do the trick. Anyway, the symptoms described lead me to a DC input error.
True, a dummy resistor would do the trick but also pull the outputs with the DC offset.

The DC input error is a logical assumption.
Situation: Both the stereo and PBTL sub-channel used to work. Then, the stereo TPA3116 chip on the same board was modified from stereo setup to PBTL configuration and worked. This modification of the other chip left this sub-channel chip to malfunction. Is there a link or are we just unfortunate that another fault appeared at the same time? A bit tricky with a board owner having only moderate diagnostic tools.
  Reply With Quote
Old 15th November 2018, 10:15 PM   #10745
voltwide is offline voltwide  Ireland
diyAudio Member
 
Join Date: Jan 2010
I assume some fault done by the user. Maybe some MLCC was mistreated and cracked? Some solder blob shorting IC-pins? There are myriades of possibilities....
  Reply With Quote
Old 15th November 2018, 10:44 PM   #10746
FauxFrench is offline FauxFrench  France
diyAudio Member
 
Join Date: Dec 2017
Location: The mountains, calm and quiet.
Quote:
Originally Posted by voltwide View Post
I assume some fault done by the user. Maybe some MLCC was mistreated and cracked? Some solder blob shorting IC-pins? There are myriades of possibilities....

You are terribly right. This is why I try to find a reference configuration from where we understand the measurements and can progress by adding functionality.
Very cooperative owner and precise in response. Just not a lot of tools. We will give it a try.
  Reply With Quote

Reply


TPA3116D2 AmpHide 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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
FS- Twisted Pear Buffalo 32S Board & System New & Unused secretriches Swap Meet 1 10th August 2009 03:17 PM
Modify & build out (2) Western Electric 300B / 2A3 Hammond monoblock amps & UTC LS-5 quality sound Tubes / Valves 0 9th May 2009 04:59 PM
Krell KSA 80 bias & dc offset check & adjust procedure Clouseaupte Solid State 3 9th August 2007 10:39 AM
DIY-AMP <ZAS> Low THD & IM high bandwith murphy Solid State 18 30th December 2005 11:28 AM


New To Site? Need Help?

All times are GMT. The time now is 05:26 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki