© 2006 Wohler Technologies Inc. ALL rights reserved
9
AMP2A
and
AMP2A-2S
User Manual P/N
821553
Rev-
B
Installation
Section 2: Operation
Mounting
The unit should be mounted where convenient for operating persons, ideally at approximately ear/eye level for best high frequency
response and visual observation of the level meters. Its superior magnetic shielding eliminates concerns about locating it adjacent
to most types of CRT monitors, including even high-resolution color monitors.
NOTE:
Be sure to set the level meter Input Level Gain Calibration and VU/PPM Display Mode DIP switch (accessed through the
top cover) BEFORE installing the unit into an enclosed rack or console. See page 17 for setting information.
Heat Dissipation
Heat dissipated by the speaker amps is conducted directly to the left side of the chassis; no special considerations for cooling are
necessary as long as the ambient temperature inside the rack area does not exceed approximately 40°C (104°F).
Sympathetic Vibration
Sympathetic vibration from other equipment (cables, etc.,) in the rack may be serious enough to interfere with the unit’s sound
quality out in the listening area. The use of thin card stock and/or felt or foam weather-stripping type materials between adjacent
vibrating surfaces, or tying up loose cables, etc., may be required to stop vibrations external to the unit.
Mechanical Bracing
Even though the unit is fairly heavy, the chassis is securely attached to the front panel at eight points along its surface, not just at
the four corners of the chassis ears. This feature will reduce or eliminate rear bracing requirements in many mobile/portable
applications. The weight of internal components is distributed fairly evenly around the unit.
Audio Connections
Connection of the audio feeds is straightforward. Please refer to the system interconnect block diagrams on pages 20 and 21 for
clarification of the general signal paths into and out of the AMP2A and AMP2A-2S units.
Analog inputs via the 3-pin female XLR connectors are configured for 200K
Ω
balanced connections. RCA connector inputs
(AMP2A only) are configured for 47K
Ω
unbalanced connections.
Electrical Interference
Care should be exercised to avoid mismatched cable types and other similar causes of undesired reflections in RF signal systems.
If severe enough, such reflections can result in undesirable electrical interference in the audio signals.
As with any audio equipment, maximum immunity from electrical interference requires the use of shielded cable; however,
satisfactory results can sometimes be obtained without it. The internal circuitry common is connected to the chassis.
AC Power
The unit's AC mains connection is via a standard IEC inlet, with safety ground connected directly to the unit's chassis. The
universal AC input (100-240VAC, 50/60Hz) switching power supply is a self-resetting sealed type, with automatic over-voltage
and over-current shutdown. There is no user-replaceable fuse in either the primary or secondary circuit.
