View Single Post
  #7   Report Post  
Old February 19th 07, 03:48 PM posted to rec.radio.amateur.homebrew
Doug Smith W9WI Doug Smith W9WI is offline
external usenet poster
 
First recorded activity by RadioBanter: Jul 2006
Posts: 82
Default Simple wideband audio amplifier circuit?

wrote:
I have been looking around the web for a complete kit for an audio
amplifier, for a circuit that I am building that needs to have a wide,
flat as possible frequency response (0Hz - 100Khz). Need to be able to
bring 400mV up to line level. I have seen several kits based on a
LM386, but I can't find any specs that show that circuit is reliable
beyond 20hz - 20Khz. I am a beginner, so keep that in mind when
responding.


What exactly are you trying to do?

400mV isn't that far from line level going into a computer soundcard.
Is there a gain, volume, or full-scale adjustment you can make in
software that'll pull up the signal?

If you do need the gain, as others say a standard op-amp circuit will do
the trick. I've found the NE5534 to be a decent low-noise choice. Stay
away from the LM386; it's great if you need a bit of audio fast and
cheap, but that's about all it's good at.
--
Doug Smith W9WI
Pleasant View (Nashville), TN EM66
http://www.w9wi.com