Cloud Electronics AE-1 - Manual (Page 6)

AE-1: Installation & User Guide 5
08-07-02 V6
12 Installing two AE-1’s to a Single Facility Input
It is possible to connect more than one AE-1 to a facility input of the Z4
II
or Z8
II
the following
diagram shows how this can be done.
12a Configuring a Z4 or Z8 to an AE-1 Location of Jumper J4
Should you wish the mic signals from the mixer to override
the AE-1 signals, set Jumper ‘J4’ on the zone board to the
‘ON’ position.
When setting the jumper(s) please ensure that you:
•
Remove the mains cable from the rear of the product
before removing the top panel
•
Only reassemble the unit using bolts/screws identical
to the original parts
12b Configuring an MPA-626 to an AE-1 Location of jumper J9
Should you wish the MPA-626 to override the AE-1
signals when Mic 1 is accessed, set jumper J9 to the ‘ON’
position.
When setting the jumper(s) please ensure that you:
•
Remove the mains cable from the rear of the
product before removing the top panel
•
Only reassemble the unit using bolts/screws
identical to the original parts
13 Solving Problems: Ground Loops & Hum
Trouble free performance can be expected if both the music and microphone sources are
derived from a double insulated mains powered unit (a unit with a two-core power cable that has
no connection to mains earth). This will ensure that the main sound system does not have an
additional power ground (earth) connection. Having more than one connection to the ‘mains
power earth’ can give rise to problems known as ‘earth loops’ which cause a constant system
‘hum’. The ‘hum’ is usually independent of any system control settings and will degrade system
performance. If a signal source connected to the AE-1 has a three-core connection to the
mains supply, and also has a safety earth connected to the metal housing, steps should be
taken to isolate the this earth termination from the sound system. The best way to isolate the
earth termination is to use a high grade, line level audio transformer with no link between the
primary and secondary windings (Diagram on the following page).