Metric Halo 2882 operating guide - Manual (Page 96)

Mobile I/O User’s Guide
88
terized by a consistent low impedance path between each device and a
common reference ground, ideally connected directly to earth ground. The
above is sometimes difficult due to electrical wiring problems in the house,
studio, or stage you are using. In the extreme case, you may need to hire a
qualified electrician to untangle and correct electrical service problems in
your working environment.
Unbalanced connections are a fact of life when interfacing with guitar amps,
and, paradoxically, guitar amps are extremely sensitive to grounding issues
since they use so much gain to achieve the effect of a “Guitar Amp”. If you
will be interfacing with guitars and guitar amps, you need to be very careful
about grounding.
Common electrical wiring approaches to residential installations, and
sub-par studio and stage installations use daisy-chained grounds for ease of
installation and economy. Unfortunately, daisy-chained grounds can intro-
duce signficant ground differentials between sockets, and these differentials
can vary depending on other loads (like refrigerators, TV’s and other house-
hold appliances) on the circuit.
Other problems with electrical service installations are improper wiring of
power phases to the three-phase service and improper connections between
the safety ground and hot legs of the three-phase service. These types of
problems tend to be characterized by loud 60Hz hums in the audio system.
Unfortunately, these types of problems extend well beyond noise in your
audio system to genuine safety hazards. If you determine that your electrical
wiring has problems beyond a simple daisy-chained ground, you should
consult a licensed electrician immediately, as ignoring these problems can
damage either you or your gear.
If you do not have a well implemented technical ground, you will want
ensure that all of the devices in your audio system are plugged into the same
phase and same ground. You can generally accomplish this by running all
your gear off of the same socket (using a power strip or power conditioner) if
your gear uses less power than is supplied by a single circuit from your pre-
mises wiring (generally 10-15 amps in residential installations and 20 amps
in commercial installations).