Hello.

I'm trying to use a laptop to record my band. However, when I hook up a
shielded cable between the "tape out" on my mixer and the "microphone
in" on my laptop, I get a tremendous amount of noise from the laptop
through the amp via the mixer, apparently picked up by the cable. The
noise consists of a whine that seems to increase in intensity when the
hard drive is active, the mouse is moved, etc.

It seems wierd to me that hooking the laptop to an -output- on the
mixer introduces noise, I could understand it better were I hooking
output from the laptop to an input on the mixer, but so be it.

Anybody had this problem and know a solution? There seem to be many
noise suppressor products on the market, but mostly they are aiming
towards car audio (alternator noise). Not sure if my problem is the
same.

I'm tempted to think that a rectifier between the laptop and the mixer
could keep the noisy signals from travelling backwards, but maybe this
is nonsense?

Thanks in advance.

LongShotBuddy wrote:
Hello.

I'm trying to use a laptop to record my band. However, when I hook up a
shielded cable between the "tape out" on my mixer and the "microphone
in" on my laptop, I get a tremendous amount of noise from the laptop
through the amp via the mixer, apparently picked up by the cable. The
noise consists of a whine that seems to increase in intensity when the
hard drive is active, the mouse is moved, etc.

It seems wierd to me that hooking the laptop to an -output- on the
mixer introduces noise, I could understand it better were I hooking
output from the laptop to an input on the mixer, but so be it.

Anybody had this problem and know a solution? There seem to be many
noise suppressor products on the market, but mostly they are aiming
towards car audio (alternator noise). Not sure if my problem is the
same.

I'm tempted to think that a rectifier between the laptop and the mixer
could keep the noisy signals from travelling backwards, but maybe this
is nonsense?

Thanks in advance.

A rectifier is a dead end. What you are trying to record is AC at
varying frequency.

It might be worth trying the set-up running on batteries. The power
supplys seem to be a problem on some laptops (not mine, so I've not got
direct experience) :-)

If this does fix it, sorry but I'm not really sure where that leaves
you, best of luck!!

Andrew

On 23 Jan 2005 18:30:03 -0800, LongShotBuddy wrote:
Hello.

I'm trying to use a laptop to record my band. However, when I hook up a
shielded cable between the "tape out" on my mixer and the "microphone
in" on my laptop, I get a tremendous amount of noise from the laptop

You're connecting a 2-4 volt output into a .005 volt input!

Connect to the line input instead and don't surprised if you've
burned out the sound chip.

"LongShotBuddy" wrote in message
oups.com
Hello.

I'm trying to use a laptop to record my band. However, when I hook up
a shielded cable between the "tape out" on my mixer and the
"microphone in" on my laptop, I get a tremendous amount of noise from
the laptop through the amp via the mixer, apparently picked up by the
cable. The noise consists of a whine that seems to increase in
intensity when the hard drive is active, the mouse is moved, etc.

Try hooking into the other input, the blue jack. It might be called "line
in" or some such.

Thanks TCS.. So you're saying that the "tape out" on my mixer (an
analog Mackie 12 channel) is 2-4 volts, and the "microphone in" on my
laptop (Dell Inspiron 1150) is expecting .005 volts..
So is the solution to somehow step down the voltage?

Thanks TCS.. So you're saying that the "tape out" on my mixer (an
analog Mackie 12 channel) is 2-4 volts, and the "microphone in" on my
laptop (Dell Inspiron 1150) is expecting .005 volts..
So is the solution to somehow step down the voltage?

Good suggestion Andrew, I should have thought of it myself :/
Thanks a bunch.

My laptop (Dell Inspiron 1150) has no "line in" jack. It has a "speaker
out" and a "microphone in". There is an adjustable gain in the
software mixer, which I'm assuming "kicks in" the preamp..

Thanks Arny.

My laptop (Dell Inspiron 1150) has no "line in" jack. It has a "speaker
out" and a "microphone in". There is an adjustable gain in the
software mixer, which I'm assuming "kicks in" the preamp..

Thanks Arny.

On 24 Jan 2005 16:49:10 -0800, "LongShotBuddy"
wrote:

My laptop (Dell Inspiron 1150) has no "line in" jack. It has a "speaker
out" and a "microphone in". There is an adjustable gain in the
software mixer, which I'm assuming "kicks in" the preamp..

If you want to do this properly, get an external USB or Firewire audio
interface for the laptop. If you want to try a bodge, attenuate the
signal going to Mic In.

Note that Mic In of domestic computers is lousy quality, even when
presented with an appropriate signal. And that the power supply of
many laptops introduces an unacceptable amount of noise. Try
recording when running on battery power, not with the mains adaptor.

On 24 Jan 2005 16:45:04 -0800, LongShotBuddy wrote:
Thanks TCS.. So you're saying that the "tape out" on my mixer (an
analog Mackie 12 channel) is 2-4 volts, and the "microphone in" on my
laptop (Dell Inspiron 1150) is expecting .005 volts..
So is the solution to somehow step down the voltage?

I was going to say use the line-in, but I just visited the dell website and
learned the dell got cheap and left it out (to save about 3 pennies).

You could step it down with a resistor divider:

R1 R2
in ----/\/\/\/\/\/--+----/\/\/\/\/\/\/------ground
\
---out

Vout = Vin * R2 / (R1+R2)

make R1 33K ohms
make R2 100 ohms

http://www.hut.fi/Misc/Electronics/c...ne_to_mic.html

Radio shack might have an attenuator cable that do exactly this. Or maybe not.


Another solution would be to use an external sound device. It'll connect
to the USB and hopefully have a line-in input.

Or use a different computer.