Using the Line-in port, I get a bad buzzing sound

  • Thread starter Thread starter Martin C
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Martin C

I am in the process of trying to convert my old vinyl LPs into CDs using a
software package called Spin It Again.

I have a slight problem with my setup in that my hifi is downstairs and the
PC upstairs. Neither are particularly easy to move, so I have bought a 15m
phono to jack cable. With this, I am able to use the software and can
monitor the LP being played and record it.

The problem I have is that no matter how I position the cable, I continue to
get a bad buzzing sound with the recording. I do not get this buzzing from
the hifi, so it must either be down to the cable run, or a problem with the
input to the PC.

The input is the line-in to the on-board sound system of an Asus A8N-SLI
Premium motherboard. Could this be the problem? Should it be using a sound
card in preference? I am tapping into the output from a phono pre-amp at the
hifi end.

Note: the noise is a definite buzzing rather than a hum that you would
expect from mains interference. If I pass the cable close to a mains cable,
then I get a bad hum as well as the buzzing. Trying to route the cable away
from other inputs into the back of the PC have not really helped at all
either.

Could this be something other than a cable run issue and something to do
with the PC? Does anyone have any ideas how to get round this?

Thanks for any help you can provide.

Martin
 
Martin C said:
I am in the process of trying to convert my old vinyl LPs into CDs using a
software package called Spin It Again.

I have a slight problem with my setup in that my hifi is downstairs and the
PC upstairs. Neither are particularly easy to move, so I have bought a 15m
phono to jack cable. With this, I am able to use the software and can
monitor the LP being played and record it.

The problem I have is that no matter how I position the cable, I continue to
get a bad buzzing sound with the recording. I do not get this buzzing from
the hifi, so it must either be down to the cable run, or a problem with the
input to the PC.

The input is the line-in to the on-board sound system of an Asus A8N-SLI
Premium motherboard. Could this be the problem? Should it be using a sound
card in preference? I am tapping into the output from a phono pre-amp at the
hifi end.
Click to expand...

Make *sure* you have MUTED and/or unplugged all unused Recording Inputs with
the Mixer applet - only leave the Line In active. If that doesn't work,
read on...
Note: the noise is a definite buzzing rather than a hum that you would
expect from mains interference. If I pass the cable close to a mains cable,
then I get a bad hum as well as the buzzing. Trying to route the cable away
from other inputs into the back of the PC have not really helped at all
either.

Could this be something other than a cable run issue and something to do
with the PC? Does anyone have any ideas how to get round this?
Click to expand...

Cabling. Temporarily move the electronics closer to your PC -
it's the easiest & cheapest thing to do even though it may not
seem so. By the time you eliminate the ground loop you have,
you'll likely have spent much more time than the move would
consume.
 
Martin said:
I am in the process of trying to convert my old vinyl LPs into CDs using a
software package called Spin It Again.

I have a slight problem with my setup in that my hifi is downstairs and the
PC upstairs. Neither are particularly easy to move, so I have bought a 15m
phono to jack cable. With this, I am able to use the software and can
monitor the LP being played and record it.

The problem I have is that no matter how I position the cable, I continue to
get a bad buzzing sound with the recording. I do not get this buzzing from
the hifi, so it must either be down to the cable run, or a problem with the
input to the PC.

The input is the line-in to the on-board sound system of an Asus A8N-SLI
Premium motherboard. Could this be the problem? Should it be using a sound
card in preference? I am tapping into the output from a phono pre-amp at the
hifi end.

Note: the noise is a definite buzzing rather than a hum that you would
expect from mains interference. If I pass the cable close to a mains cable,
then I get a bad hum as well as the buzzing. Trying to route the cable away
from other inputs into the back of the PC have not really helped at all
either.

Could this be something other than a cable run issue and something to do
with the PC? Does anyone have any ideas how to get round this?

Thanks for any help you can provide.

Martin
Click to expand...

This won't help solve the problem. At least immediately.

Record a number of seconds of the buzzing sound.

Open the recording in Audacity (I'm using the beta version)

http://audacity.sourceforge.net/download/windows

Highlight a representative section of the buzzing sound recording
with the mouse (wipe over it).

Select Analyse:Plot Spectrum from the menu at the top.

Change bottom axis to "Log frequency". As you mouse along,
the peak finder will identify the frequency of the central peak.

If the buzzing is line related, it will be a harmonic of the line
frequency. For example, if you are on 50Hz AC, then maybe you'd
see a 150Hz peak, if there was a lamp dimmer throwing off noise
into the AC wiring of the home.

There is an article here with some suggestions. There is an
assumption here, that the reader has some knowledge of electronics.
The reason I got to this page, is I wanted to find out what was
inside the following 270-054 unit.

http://www.smr-home-theatre.org/Ground-Loops/

The following is a ground loop isolator. The previous article says
this uses transformers inside the blob, to couple signal without
providing a path for noise to travel. With unshielded wires acting as an
antenna, it will still be possible to be pestered by noise, even
if using this gadget. I might try some coax to eliminate that.
There would be a coax for the right channel, and a coax for the
left channel, and the necessary connectors to allow hooking up with
RCA connectors. It'll probably cost a small fortune in connector
adapters, to hook all that crap together.

Ground Loop Isolator 270-054 $16.99
http://www.radioshack.com/product/index.jsp?productId=2062214

So the ground loop isolator breaks a conducted noise loop, but
if the problem is actually a radiator of noise, shielding may
help with that.

Another option, would be a wireless transmitter receiver, to pass
analog a distance. That would cost probably 10x the above, and
to boot, probably adversely affect the frequency response of the
recorded content. This one is not that expensive, but it contains
no frequency response spec, and that means trouble.

http://rsk.imageg.net/graphics/uc/rsk/Support/ProductManuals/1502574_PM_EN.pdf

HTH,
Paul
 
You have a "Ground" problem. Hi-Fi/Turntable and PC need to be bonded to a
common ground. Run a wire from the "Ground" post on the back of the
Hi-Fi/Turntable to the PC and connect to the back of the case. Use one of
the case screws, not power supply mounting screws. Cause is the magnetic
pick up on the turntable.

Hope this helps. I had the same "buzz" when I first tried vinyl to CD.

JHG
 
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