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Thread ID: 26702 2002-11-03 06:45:00 How to reduce Sound input volume - way too high John W (523) Press F1
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95600 2002-11-03 06:45:00 Im recording sound from a video recorder, the cable is p[lugged into the Microphone input on the Soundcard, but with the Volume Control, Mic level switch down to zero, Mic Boost switched OFF, the volume is way too high. It noticably distorts at anything above quiet conversation level,

What I think I need is a resistor in series (soldered into the cable and insulated from the screen cable surrounding it) with the input line, but what value.

Any ideas?

Thanks.....John.
John W (523)
95601 2002-11-03 06:48:00 you need to plug it in to a audio input NOT a microphone input. tweak'e (174)
95602 2002-11-03 06:59:00 That is a horrible mismatch, and never intended to work that way. Do you not have a "line in" socket, as this is made for the impedance and voltage match of the VCR.

The VCR line out (AV) is about 0.7 volts, and somewhere from 10k to 47k impedance.

The microphone input is of unknown impdedance, but is only designed for a few mV (.002 v or so)

You need to find the impedance of the mic input, but its likely to be in the order of a few hundred ohms to a couple of thousand ohms.

So you need more than a series resistor, you need a bridge arrangement. Perhaps a 2k2 across the mic, a 47k across the AV line and a coupling resistor between the two which gives you the right volume.

Unless the quality is not important...but you will really need the 2k2 across the mic, start with 100k coupling, but buy a range. (only a few cents each)
godfather (25)
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