6
© 2006 Wohler Technologies Inc. ALL rights reserved
AMP1A-4S/-10S/-LP4S/-LP10S
User Manual P/N
821527
Rev-
B
Section 1: General Features and Specifications
Installation
Mounting
NOTE:
Be sure to set the level meter Gain Calibration and Display Mode DIP switch (accessed through the top cover) BEFORE
installing the unit in the rack or console. See page
15
for setting information.
The unit should be mounted where convenient for operating persons, ideally at approximately ear level for best high frequency
response. Its superior magnetic shielding eliminates concerns about locating it adjacent to most types of CRT monitors, including
even high-resolution color monitors.
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 diagram on pages
18
and
19
for
clarification of the general signal paths into and out of the
AMP1A Series
units.
Phoenix connector inputs on the analog switching PCB (919013) are 90K
Ω,
balanced. Care should be exercised to avoid mis-
matched cable types and other similar causes of undesired reflections in RF signal systems.
Electrical Interference
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.
