Soundcard Input Isolater/Saver - diyAudio
Go Back   Home > Forums > General Interest > Everything Else

Everything Else Anything related to audio / video / electronics etc) BUT remember- we have many new forums where your thread may now fit! .... Parts, Equipment & Tools, Construction Tips, Software Tools......

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 15th October 2010, 11:14 PM   #1
cuibono is offline cuibono  United States
diyAudio Member
 
cuibono's Avatar
 
Join Date: May 2006
Location: City of Angles
Default Soundcard Input Isolater/Saver

I've damaged three out of four inputs on my soundcard - time to do something about it! Looking around, this isn't new territory. I thought I might develop it some more, hopefully.

As it turns out, the line input of my soundcard is DC coupled. It looks like there may be diodes protecting the input opamp (a 5532), but I'm not sure what they are doing, because something has been damaged - the noise floor is up 40dB...

So, I want to incorporate a few things:

-a DC block/HP filter, around 10Hz
-a LP filter for ultrasonic stuff, around 100kHz
-zener diodes, to protect from over-voltages
-an differential instrumentation amp, to prevent ground loops (has been handy in the past)
-a possible buffer on the output, to keep the filters well behaved

Here is the simplest option:
Click the image to open in full size.
It has a voltage divider that attenuates the same amount as the gain of my amplifier. The LPF is about 10Hz, the HPF is about 100kHz, and the zeners should be 2.2V versions.

Here it is with opamps:
Click the image to open in full size.
Still a work in progress, but this is about it. There is no input attenuator anywhere. The third opamp has 100V/V gain, which is something I use with my scope to look at small signals.

I'm thinking battery power. I'll draw up boards and BOMs, and post them.

Any feedback?
  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
Socket Saver Kashmire Tubes / Valves 2 3rd January 2010 01:49 AM
need help to build Electricity power saver space2000 Power Supplies 16 7th December 2008 05:04 PM
0.300 VDC (from soundcard) on LM3875 GC input !!! Leglandu Chip Amps 28 1st February 2008 03:39 PM
Soundcard input isolation Mr Evil Everything Else 8 29th June 2005 08:09 PM
battery isolater kaukasion Solid State 0 16th July 2003 06:53 PM


New To Site? Need Help?

All times are GMT. The time now is 03:35 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