SignalQ Sites:
L1G3R Information Systems - NetAdminTools - SpotBridge
RoboCoop - AreWeDown - SysAdminTools - NAW
Xfig - Gold Loaf - GeekPapa - FixGMC - FixRambler
GNU/Linux | Homebrew designs | Perl | Microcontrollers | Graphics | Z-80 | FreeDOS | Electronics | Odyssey 2 | 8048 | Other/Msc.

Last 30 Days | Last 60 Days | Last 90 Days | All Articles/Links
·Homebrew Designs
·All Categories
·Other SignalQ Websites

Make Your Cheap Sound Card Louder
Topic:Electronics   Date: 2003-08-10
Printer Friendly: Print   Mobile View: mobile

<<  <   >  >>

I have a cheap sound card integrated into my motherboard. I've always been tempted to purchase a better sound card with an amplifier and better speakers. I'm too cheap, though, really. I have a couple of fairly nice speakers that aren't amplified. They are left over from an HP Pavillion system, and are quite frequently available at auction. I just need the amplifier part to make my multi-media experience complete. The LM4752 is a single component stereo audio amplifier that is perfect for this task. Better yet, it costs less than three bucks in single quantities.

Here is a picture of the speakers and the amp on top of my monitor:

I bought a fancy box from Radio Shack, but I have a better plan for it. I'm not driving much with the amp, so I just threw it all into a box I had laying around and duct taped it up. Works fine for me. :)

There are circuit board and application notes available in pdf form here. I made a .png file of four of the boards, which you may find useful here.

How about some pictures! Here is the bare, etched board:

A pile of parts:

I used two to-220 heatsinks. One bent straight, and both with heat sink compound:

Here is the whole board soldered up:

Instead of a variable resistor, I used a fixed 100 ohm resistor on the amp inputs to cut down on noise. I'm listening to Stevie at 75% volume and it is plenty loud enough. There is something about this particular collection that goes well with soldering and GNU/Linux... not sure what, maybe it is simply the blue lamp. Anyway... how about some more pictures, eh?

Here is a closeup of the parts on the circuit board. I used 2.2 ohm resistors instead of the 2.7 recommended, because I had them. In this picture I was using 1k resistors on the inputs. 100 ohms cuts down on the amount of stray electrical noise picked up when nothing is coming out of the sound card. Actually, by using this method, this is the first amplified speaker add-on I've used that you don't hear buzzing on.

I'm trying some Illinois Bronze Triple-Thick Coating Crystal Clear Glaze No. 0500 on the bottom of the board to protect it from corrosion.


Please read our Terms of Use and our Privacy Policy
Microsoft, Windows, Windows XP, Windows 2000, and NT are either trademarks or registered trademarks of Microsoft Corporation. is not affiliated with Microsoft Corporation. Linux is a registered trademark of Linus Torvalds. All logos and trademarks in this site are property of their respective owner. Copyright 1997-2013