Parasound A 52 - Manual (Page 17)

TECHNICALLY SPEAKING continued
15
The ideal of zero voltage ground for all the compo-
nents in a system is practically impossible, because
some resistance between the ground points of differ-
ent components is inevitable. By keeping components
close together with their power cords plugged into a
common AC outlet or power strip, you’ll avoid the
problems created by resistance in the house’s wiring.
Hum and buzz is also caused when unwanted voltage
flows through multiple component ground points
called ground loops. Here are three tips to avoid
ground loops:
1. Use balanced input lines with your Parasound A 52.
(See Balanced and Unbalanced Lines in this section)
2. When rack mounting, always use insulated “shoul-
der” washers. These break the ground loops caused
by metal-to-metal contact between the rack, the
components, and their rack-mount bolts. Extra wash-
ers are available from rack manufacturer Middle
Atlantic Products, www.middleatlantic.com.
3. Use the Ground switch on the A 52 to eliminate
most ground loops. This separates the A 52 ’ s sig-
nal input ground from its chassis ground to isolate
unwanted voltage in the ground shield of the
unbalanced (RCA) input cable. Be sure your system
installation is finished before you try moving the
Ground switch from its Normal to its Lift position.
Ch 1 Ch 2 Ch 3 Ch 4 Ch 5
Input Balanced
Unbalanced
Input Balanced
Unbalanced
Input Balanced
Unbalanced
Input Balanced
Unbalanced
Input Balanced
Unbalanced
Man
Balanced
Inputs
Unbalanced Input 12 V Output
Audio Sensitivity
50 mV 250
Ground
Normal
Lift
WARNING
To Prevent Fire Or Shock Hazard,
Do Not Expose This Unit To Rain
Or Moisture.
Fuse
T15A/250V1-115V Area
T8A/250V-230V Area
AC 115V 60Hz
AC 230V 50Hz
Power Consumption: 1350W
Parasound Products, Inc.
San Francisco, CA USA
Manufactured under
license from Lucasfilm
Ltd. Lucasfilm and THX
are registered Trademarks
of Lucasfilm Ltd.
CAUTION
To Prevent Electric Shock, Do Not
Remove Cover. No User-Serviceable
Parts Inside, Refer Servicing To
Qualified Service Personnel.
Auto Turn On
L U C A S F I L M L M
Ground Switch, set to up position