Look over this amp board layout please. - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State

Solid State Talk all about solid state amplification.

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 November 2007, 02:04 AM   #1
Account disabled at member's request
 
MJL21193's Avatar
 
Join Date: Mar 2007
Default Look over this amp board layout please.

It pains me to do this, but I need more input ( on the board layout) than I'm currently getting on the original thread where this amp was developed:

Help with this amp? A patchwork product of simulation

This is a low distortion, high power (150+watts @ 8 ohms) design. It's a two sided board, with a poured ground plane on the top. It uses 56 volt rails and has on board power supply (bridge, smoothing caps, rail fuses).

Please take the time to check it out and give me suggestions as to how to improve it.
In the pic below: board on the bottom has the ground plane added. Board size is about 3" x 8" (7.5cm x 20cm).
I will post the schematic next.
Attached Images
File Type: gif board1.gif (56.6 KB, 395 views)
  Reply With Quote
Old 20th November 2007, 02:05 AM   #2
Account disabled at member's request
 
MJL21193's Avatar
 
Join Date: Mar 2007
Here's the schematic:
Attached Images
File Type: gif a.gif (29.6 KB, 422 views)
  Reply With Quote
Old 20th November 2007, 08:09 AM   #3
h_a is offline h_a  Europe
diyAudio Member
 
h_a's Avatar
 
Join Date: Sep 2006
Location: Graz, Austria
I have not compared the layout to the schematic, however your general layout looks very nice!

All the best, Hannes
  Reply With Quote
Old 20th November 2007, 11:29 PM   #4
Account disabled at member's request
 
MJL21193's Avatar
 
Join Date: Mar 2007
Quote:
Originally posted by h_a
I have not compared the layout to the schematic, however your general layout looks very nice!

All the best, Hannes

Thanks Hannes,
Well, once again, a huge response.
I'll go with it.
  Reply With Quote
Old 21st November 2007, 03:17 AM   #5
diyAudio Member
 
Join Date: Jul 2003
Location: Dona paula, Goa
Default Couldn't help pointing out...

The negative supply cap is very far from the o/p transistor. These high current connections should be the shortest.

Gajanan Phadte
  Reply With Quote
Old 21st November 2007, 04:05 AM   #6
Account disabled at member's request
 
MJL21193's Avatar
 
Join Date: Mar 2007
Default Re: Couldn't help pointing out...

Quote:
Originally posted by gmphadte
The negative supply cap is very far from the o/p transistor. These high current connections should be the shortest.

Gajanan Phadte

Hi Gajanan,
I tried to make the rails as short and wide as possible, while still leaving space for the output devices to mount to the heatsink. I thought that I'd struck a pretty good compromise since in many designs, these leads are wire from PS board to amp board - wires that may be twice that length and possibly too thin.
  Reply With Quote
Old 21st November 2007, 05:22 AM   #7
diyAudio Member
 
Join Date: Jul 2003
Location: Dona paula, Goa
I think u should forget the one-side-power-connector approach and shift the caps to either side of the board. e.g. as in MikeB's Symasym

Remember, longer, high current tracks will induce signal in the nearby tracks, more inductance...

Anyhow, you are the best judge.

Gajanan Phadte
  Reply With Quote
Old 21st November 2007, 08:05 AM   #8
jaycee is offline jaycee  United Kingdom
diyAudio Member
 
Join Date: Apr 2004
Location: Norwich, UK
Personally I would keep the main supply capacitors + rectifier off board. Then I would have the power connections from the supply to the amp as near to the output transistors as possible, with some local decoupling.

If you really want to do it this way, then the one layout I have seen that impressed me in this regard was SuzyJ's power amp. She has the layout available on her site:

http://www.littlefishbicycles.com/poweramp/index.html
  Reply With Quote
Old 22nd November 2007, 12:50 AM   #9
Account disabled at member's request
 
MJL21193's Avatar
 
Join Date: Mar 2007
Quote:
Originally posted by gmphadte
I think u should forget the one-side-power-connector approach and shift the caps to either side of the board. e.g. as in MikeB's Symasym

Remember, longer, high current tracks will induce signal in the nearby tracks, more inductance...

Anyhow, you are the best judge.

Gajanan Phadte

No, I'm not the best judge, just a raw amateur.
I thought about putting the supply caps on either side of the board, but decided against that, as then there would be long leads from the bridge.
I was thinking the ideal place for the power supply was on the other side of the heatsink., but this would severely cripple chassis layout, convection and increase board size dramatically.It would be just as well to use a separate PS board as to do that.

Again, I think I have struck a good compromise here. The lead from the negative rail is a bit longer than the positive rail, but I don't see that as a problem.
  Reply With Quote
Old 22nd November 2007, 01:28 AM   #10
Leolabs is offline Leolabs  Malaysia
diyAudio Member
 
Leolabs's Avatar
 
Join Date: Dec 2004
Location: Bukit Mertajam
Send a message via MSN to Leolabs
Are the electrolytic caps close to the heatsink???
  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
Board layout design Valvomaniac Tubes / Valves 7 21st March 2007 01:08 PM
Best practices for board layout??? gmikol Parts 6 10th February 2006 05:56 PM
Suggestions on board layout Bas Horneman Everything Else 14 26th March 2004 09:00 AM
Board Layout. jleaman Everything Else 8 4th May 2003 07:18 PM


New To Site? Need Help?

All times are GMT. The time now is 11:40 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