SMD Preamp/Buffer design - 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 23rd January 2006, 05:28 AM   #1
Wynand is offline Wynand  South Africa
diyAudio Member
 
Wynand's Avatar
 
Join Date: Mar 2005
Location: Cape Town
Default SMD Preamp/Buffer design

I've been working on this design over the last week.

It's a input buffer circuit with LM2940 and LM2990 voltage regulators.

The LP filter is set to approx 3hz and the HF Filter to 100-140 Khz.

These values were suggested by Peranders (thank you).

Any comments/suggestions?

The red is the top layer with all the tracks.
Blue is vias and green is the bottom layer(Ground plane).

Here's the PSU Schema
Attached Images
File Type: jpg psu schematic.jpg (16.4 KB, 343 views)
  Reply With Quote
Old 23rd January 2006, 05:29 AM   #2
Wynand is offline Wynand  South Africa
diyAudio Member
 
Wynand's Avatar
 
Join Date: Mar 2005
Location: Cape Town
Here's the Buffer schematic
Attached Images
File Type: jpg buffer schematic.jpg (21.0 KB, 331 views)
  Reply With Quote
Old 23rd January 2006, 05:32 AM   #3
Wynand is offline Wynand  South Africa
diyAudio Member
 
Wynand's Avatar
 
Join Date: Mar 2005
Location: Cape Town
....and the layout.
Attached Images
File Type: jpg pcb layout.jpg (94.0 KB, 300 views)
  Reply With Quote
Old 23rd January 2006, 06:13 AM   #4
Nordic is offline Nordic  South Africa
diyAudio Member
 
Nordic's Avatar
 
Join Date: Sep 2005
Wynand... if you are going to make some of those.. won't you make me a spare PBC too?
  Reply With Quote
Old 23rd January 2006, 07:08 AM   #5
Wynand is offline Wynand  South Africa
diyAudio Member
 
Wynand's Avatar
 
Join Date: Mar 2005
Location: Cape Town
I'm actually hoping there's enough interest to get them professionally made.
  Reply With Quote
Old 23rd January 2006, 07:22 AM   #6
Arius is offline Arius  United States
diyAudio Member
 
Join Date: Mar 2004
Location: California
If you require professionally made PCB's, give www.pcbfabexpress.com a try. For a board like yours, it will cost US$13 each (minumum order of 5pcs) plus overseas shipping.

If you have one or two people interested, that ought to make the cost reasonable.

Disclaimer: My only relationship with them is that of a happy customer.

Back to the pre-amp, it seems fairly basic. Is that what you really want? Suggestions for improvement might be something like a buffer followed by the volume control, then an active gain stage (2 op-amps per channel). Other enhancements might be separate regulation (if not separate rails altogether) for each channel, use of good quality opamps and potentiometers, improved decoupling/filtering, relay-switched output, optional output coupling cap, etc.
  Reply With Quote
Old 23rd January 2006, 07:23 AM   #7
Nordic is offline Nordic  South Africa
diyAudio Member
 
Nordic's Avatar
 
Join Date: Sep 2005
These look quite handy for multichannel applications because of the small size...
  Reply With Quote
Old 23rd January 2006, 10:12 AM   #8
Wynand is offline Wynand  South Africa
diyAudio Member
 
Wynand's Avatar
 
Join Date: Mar 2005
Location: Cape Town
Oops... seems I cant find most of the SMD components.

I'll have to revert to push through components.

I'll be a bit bigger but not by THAT much.
Another bonus would be being able to etch it myself!!!
  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
B1 Buffer Preamp BOM davidfmartin Pass Labs 1 12th December 2011 10:27 PM
help design SE preamp with mosfet buffer and step-up transformer. AudioGeek Solid State 0 19th January 2005 03:02 AM


New To Site? Need Help?

All times are GMT. The time now is 10:33 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