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

Chip Amps Amplifiers based on integrated circuits

Critique my PCB! Yet another parallel LM3886
Critique my PCB! Yet another parallel LM3886
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 10th June 2018, 04:31 PM   #11
abza is offline abza  South Africa
diyAudio Member
 
abza's Avatar
 
Join Date: May 2014
Thanks @00940 - great reference.

Okay, I'm starting from scratch. Before I get too carried away, I just wanted to get an opinion on the following pour layout, using suggestions above. The power pours are now much larger and consistent in thickness, the outputs are now chunky instead of individual traces. The entire ground plane (on the bottom) has been flooded, with some separation near the input section as per @tomchr's feedback in this thread.

I've not routed anything else except for the two output traces from the LM3886es to the output pours - attached are just the pours as a work in progress, the text/component placement is still a little messy. But does this look good from a general grounding and pour perspective?
Attached Images
File Type: jpg v2 - Top.jpg (147.7 KB, 192 views)
File Type: jpg v2 - Bottom.jpg (211.7 KB, 192 views)
File Type: png v2-Schematic.PNG (41.4 KB, 177 views)

Last edited by abza; 10th June 2018 at 04:33 PM. Reason: additional info
  Reply With Quote
Old 10th June 2018, 06:16 PM   #12
asuslover is online now asuslover  Romania
diyAudio Member
 
Join Date: Aug 2016
Location: USA
Critique my PCB! Yet another parallel LM3886
I see that you insist in having v+ in one side and v- in the other side of the board, that means you'll have unnecessary longer cables from the power supply to the amplifier board , and I think would not look so neat. Am I the only one who's not a big fan of diagonal components?
  Reply With Quote
Old 10th June 2018, 06:50 PM   #13
abza is offline abza  South Africa
diyAudio Member
 
abza's Avatar
 
Join Date: May 2014
@asuslover - I literally just finished an option where the power connectors are grouped together

Attached - still keen to see whether either of these two versions are better in terms of grounding and pour placement.
Attached Images
File Type: jpg v3-Top.jpg (147.2 KB, 179 views)
File Type: jpg v3-Bottom.jpg (75.4 KB, 165 views)
  Reply With Quote
Old 10th June 2018, 08:38 PM   #14
00940 is offline 00940  Belgium
diyAudio Member
 
00940's Avatar
 
Join Date: Sep 2003
Location: Liège
You might have a look at this too: DIY BPA300 6x LM3886 300W audio Amplifier
__________________
All that is excessive is insignificant. Talleyrand
  Reply With Quote
Old 10th June 2018, 09:22 PM   #15
asuslover is online now asuslover  Romania
diyAudio Member
 
Join Date: Aug 2016
Location: USA
Critique my PCB! Yet another parallel LM3886
Looks much better, I can't see how pins no 3 for the ic s are connected.I would connect them to ra6/ra4 on the bottom of the board so you can leave V+ Copper pour as wide is possible.
  Reply With Quote
Old 10th June 2018, 09:57 PM   #16
Mark Whitney is online now Mark Whitney  Netherlands
diyAudio Member
 
Mark Whitney's Avatar
 
Join Date: Feb 2013
Location: Netherlands
The output ground is missing in both the schematic and PCB.
__________________
Regards Mark.
  Reply With Quote
Old 11th June 2018, 07:43 AM   #17
abza is offline abza  South Africa
diyAudio Member
 
abza's Avatar
 
Join Date: May 2014
Quote:
Originally Posted by asuslover View Post
Looks much better, I can't see how pins no 3 for the ic s are connected.I would connect them to ra6/ra4 on the bottom of the board so you can leave V+ Copper pour as wide is possible.
As mentioned the example images are pretty much just the pours for now, but will keep this in mind. Thanks for the feedback! Will forge ahead with this general layout.

Quote:
Originally Posted by Mark Whitney View Post
The output ground is missing in both the schematic and PCB.
@Mark - this is intended for use in a balanced/parallel setup - another identical board is handling (what would be) the output ground - see here.
  Reply With Quote
Old 11th June 2018, 08:33 PM   #18
asuslover is online now asuslover  Romania
diyAudio Member
 
Join Date: Aug 2016
Location: USA
Critique my PCB! Yet another parallel LM3886
Those halves of your amp should be working individually , I would focus on designing an fully working amp (output ground is a must) and then bridge 2 of them.
This is how Tom is suggesting this to be done.
Attached Images
File Type: png IMG_8034.PNG (124.0 KB, 67 views)

Last edited by asuslover; 11th June 2018 at 08:38 PM.
  Reply With Quote
Old 11th June 2018, 10:16 PM   #19
abza is offline abza  South Africa
diyAudio Member
 
abza's Avatar
 
Join Date: May 2014
Okay, what I'm calling version "4", attached.

Lots has changed, used the ground layout settled on with @asuslover - I'm preferring the grouping of the power pins as well, which has been consolidated into a fat Molex style power connector.

Ballast resistors (0.1R) added as well.

Most of the heavy-duty connections are now handled by pours, with a few traces on the top (and a couple on the bottom) handling signal paths.

Things to do: add an output ground, add mounting holes.

Is this looking any better? Worse? Hit me
Attached Images
File Type: jpg v4-Schematic.JPG (71.9 KB, 69 views)
File Type: jpg v4-PCB.jpg (233.0 KB, 68 views)
File Type: jpg v4-Top.jpg (144.5 KB, 72 views)
File Type: jpg v4-Bottom.jpg (76.2 KB, 55 views)
File Type: jpg v4-Render.jpg (100.7 KB, 67 views)
  Reply With Quote
Old 11th June 2018, 10:16 PM   #20
abza is offline abza  South Africa
diyAudio Member
 
abza's Avatar
 
Join Date: May 2014
Quote:
Originally Posted by asuslover View Post
Those halves of your amp should be working individually , I would focus on designing an fully working amp (output ground is a must) and then bridge 2 of them.
This is how Tom is suggesting this to be done.
Beat me to it! This is on the to-do list for v5 Thanks!
  Reply With Quote

Reply


Critique my PCB! Yet another parallel LM3886Hide 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
HELP with LM3886 X3 in parallel. Aguilabrava Chip Amps 45 7th November 2016 08:54 AM
Parallel TDA2052 vs Parallel LM3886 for subwoofer goldyrathore Chip Amps 24 21st October 2013 06:50 PM
LM3886 x 2 in parallel jmar Chip Amps 46 24th October 2009 04:53 PM
LM3886 parallel PCB's jmillerdoc Chip Amps 0 27th May 2009 09:26 PM
Are two separate lm3886 = 2*lm3886 in parallel or bridge mode rs1026 Chip Amps 11 21st October 2004 11:24 AM


New To Site? Need Help?

All times are GMT. The time now is 07:21 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki