[ddots-l] Re: To Gord or anyone else
- From: "Bryan Smart" <BSmart@xxxxxxxxx>
- To: <ddots-l@xxxxxxxxxxxxx>
- Date: Mon, 5 Mar 2007 14:17:34 -0500
Hi Omar.
This 60Hz hum is caused by phasing between the different power sources of
your equipment. Electrical current in North America alternates at 60Hz, but
is only roughly maintained at this frequency. Further, other devices in your
home that are drawing electricity can affect the pattern of the electrical
signal. You may notice that you can affect the severity to some extent by
turning up and down individual channels on your mixer. Sometimes, you may
even be able to get the hum to go away with the right combination of levels.
Of course, this is not a fix, as you need to be able to set the levels to
whatever is appropriate for mixing.
The elegant approach to fix this is to buy a device called a power
conditioner. It is sort of like a power strip, but contains circuitry to
clean up the electrical signal that you're equipment is receiving from the
wall outlet. You would plug all of the equipment in your DAW rig into this
device: computer tower, computer monitor, mixer, monitor speakers,
synthesizers, etc.
The cheaper approach is to use an uninterruptible power supply in
combination with a standard power strip. The uninterruptible power supplies
are designed to maintain constant power, so have internal circuitry to draw
from both the wall and their internal battery in order to produce their own
electrical signal. The signal won't be as pure as with a power conditioner,
but it will be reasonably clean, and will be isolated from interference from
the other equipment in your home/business. UPSes are cheap. You buy one, and
plug all of your equipment into it, just as you would a power conditioner.
The catch is that these devices won't all handle a huge power load. They're
designed to keep a computer running in the event of a power failure. You can
hook a computer, and some small amount of audio gear up to one of these, but
don't plug large amps into them. If you have equipment that draws lots of
power, then you must get a power conditioner.
Finally, you have the ghetto studio approach. All you need for this one is a
large power strip. Since the hum from your equipment is caused by the
phasing of the electricity from several sources, you get rid of the problem
by putting everything on the same source. Plug all of your equipment into
the power strip, and plug that power strip into an outlet. When I say all of
your equipment, I mean all of it. Even the monitor, even the base station
for your wireless keyboard...all of it. If even one device in your rig is
connected to another wall outlet, it will cause hum to appear in other
equipment in your rig. Warning warning warning! If you have a simple rig
with a computer, monitor, mixer, monitor speakers, and some small
accessories that use AC adaptors, then this will work for you. You could
probably chain power strips and be alright. However, don't even think about
this if you have an amp, more than one keyboard, etc. The problem is that,
in this approach, you're pulling all of the electricity for your rig through
one outlet. If you pull too much, you could blow a fuse/breaker, cause the
wiring in your walls to heat up, and potentially cause a fire. A good rule
is, when hooking devices up this way, to use no more than 3 high powered
devices (tower, monitor, small amp), and no more than 6 small devices
(wireless keyboard, mixer, audio interface power/external optical drive,
headphone amp, etc). Also, I wouldn't attempt this if you're working in an
older house/building with older wiring. You don't run any of these dangers
with either the power conditioner or UPS, as they have internal circuits
that will trip the power out if you try to draw more than the circuit can
handle.
You'll need to choose the approach that is best for you. The last one will
work for free if you have a small rig. The approach with the UPS is good if
you're on a budget. If you can afford it, though, the power conditioner
approach is the best way to go.
I had to live with hum for a long while before I figured out why it was
there. I was so happy when I could finally get it out of my speakers and
recordings. Everything was soooo quiet, finally! I wish you a similar
experience.
Bryan
_____
From: ddots-l-bounce@xxxxxxxxxxxxx [mailto:ddots-l-bounce@xxxxxxxxxxxxx] On
Behalf Of Omar Binno
Sent: Monday, March 05, 2007 1:26 PM
To: ddots-l@xxxxxxxxxxxxx
Subject: [ddots-l] To Gord or anyone else
Hi Gord and everyone else:
I'm getting a small staticky or grounding type of noise in my audio
recordings where there are no instruments playing. Gord, I don't know if you
remember, when you were here, you determined that this grounding noise was
coming from the computer's soundcard, and that nothing could really be done
about it. Whatever it is though is also coming out in the audio recordings.
It's covered up when the beat is playing, but if there is a blank spot you
can hear the noise in the background. Any help is greatly appreciated.
Thanks.
Omar Binno
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