Film-Tech Forum ARCHIVE: A-Chain readings using laptop mic input

This is topic A-Chain readings using laptop mic input in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Frank Dubrois (Member # 3042) on 06-24-2006, 02:16 PM:

I know its definately the way to do it. But my external sound card wont be here until next week, so I made a set of cables to try this out and maybe compare the readings (just because I get bored). The dolby tone didnt even register. Would that be common? I thought I'd at least get a reading, but it was flatline. I thought the mic input would at least work..just not be as accurate.

Posted by Monte L Fullmer (Member # 2797) on 06-24-2006, 04:01 PM:

Where are you trying to get the source from? Mic input doesn't like higher current sources like what an AUX output creates...doing such a feat requires a 40 to 50 dB current attenuation before heading into the mic input..

..you possibly could have toasted the mic circuit on your laptop doing this..

-Monte

Posted by Frank Dubrois (Member # 3042) on 06-24-2006, 04:11 PM:

lol...oh good. I dont use the mic for anything anyway.

Posted by Frank Dubrois (Member # 3042) on 06-27-2006, 04:25 PM:

FYI...it does damage the either the sound card or the speakers. i hear a cracling noise whenever the speakers are used or the volume is adjusted. Oh well...

Posted by Charles Greenlee (Member # 3856) on 06-27-2006, 11:04 PM:

Had it have been a desktop or tower, I'd say scew it and just replace the soundcard. But a laptop? I'd be Po'ed.

Posted by Frank Dubrois (Member # 3042) on 06-27-2006, 11:43 PM:

Well, I wanted to try it. Its a little annoying that it happened, but not totally unexpected. I dont really use sound with the laptop anyway, so its not a big deal.

Posted by Charles Greenlee (Member # 3856) on 06-29-2006, 12:43 AM:

You live, you learn. How many of today's great discoveries blew up on their inventors when they were just experiments in someone's garage? You may have a very valid idea, just forgot to check the signal strength. Next time you try it, build an attenuating circuit to drop the signal down to tolerances. Good thinking though.