Help Recording into Computer

[Magnusfarce]

If I had more time, I'd do some proper research, but instead, I'm going to
ask for some "walk-through" type help for this little project. There is a
message stored on my home phone that I'd like to pull off into my desktop,
rip to a wave file and burn onto a CD. The message in question of the first
ever left by my child, and my wife likes to keep it on the machine for
sentimental reasons. I want to burn it so we can keep it (and also get the
darned thing off the phone).

I know a fair amount of electronics so I should be able to tap the phone
speaker leads and record it while I play it from the machine. This should
be line level output and I assume the computer would be able to handle this
signal. I also know how to work with Nero a bit and can probably rip the
resulting audio file into wav. format and burn it to CD without too much
trouble.

What I don't know is how to use the record function of my computer. I have
W2k on a solid machine, and I know there is a microphone input on the
motherboard. Can anyone walk me through the record process? I don't even
know if it's a built-in Windows function or if I need some additional
software. I also don;t know for sure whether the mic input will handle a
line level signal. In any case, I've only got a couple of days to get this
done, so any help would be appreciated, even if its just a pointer to a
source of info. TIA.

- Magnusfarce

 

[3c273]

Win2k has Sound Recorder, it's in Accessories\Entertainment. It's pretty
basic and records low quality for up to 2 minutes. This should be fine for
answering machine output. If you want something with a little more control,
try Audacity (freeware) from http://audacity.sourceforge.net . You can set
the sensitivity of the mic input by double clicking on the speaker in your
system tray and choosing "properties" from the options menu. Click the
radio button labeled "Recording" and make sure the box next to "microphone"
is checked. Now click "OK" and go to the optrions menu and click "advanced
controls", this will give you an "Advanced" button under the microphone
slider. If you open that, there will be an additional gain control and
bass/treble controls (depending on your sound card). Anything you record
will already be in wav format so just burn it with Nero. HTH.
Louis

 

[Steve Nielsen]

It would be better to use a microphone. The speaker output is NOT line
level, the impedance is much too low (meaning voltage too high) for line
level recording and it will overdrive your line input on the sound card
and possibly damage the input without using a voltage divider circuit to
lower the output from the answering machine, so don't do it that way.
Just use a mic.

There is a Sound Recorder program in Windows under
Programs/Accessories/Entertainment. It will only record in mono and for
a couple of minutes, but that ought to do it. If the message is longer
then you'll need a seperate recording program. Lots of shareware out
there. Goldwave is good.

Steve

 

[Magnusfarce]

I understand what you are talking about given that the voltage driving the
speaker should be much higher than usually seen at the mic input. However,
I'd like to avoid the added degradation from the speaker/microphone
combination. I can set up a voltage divider to drop the speaker voltage but
I would be guessing at values. I suppose trial and error would work, but
being this is a surprise, I may not have access to the phone for long
periods of time. Any guesses as to how much to split or drop the voltage to
make it safe for the mic input?

- Magnusfarce

 

[Steve Nielsen]

Start here:

http://www.epanorama.net/circuits/speaker_to_line.html

At the output of the ciruit shown I would add a 1uF capacitor in series
to block any possible DC voltages present from hitting the soundcard.
And use the soundcard's LINE input, not MIC input.

Steve