LD PA 400, PA 1000, PA 800, PA 1600X User Manual

PA 400
PA 800
PA 1000
PA 1600X

USER’S MANUAL

In choosing a power amplifier from the LD Systems' PA series range, you have chosen a power
amplifier designed using traditional, reliable technology with a conventional toroidal
transformer power supply, but super-fast, latest generation high-performance bipolar
transistors. With the exception of the PA400, all amplifiers operate in Class H mode, i.e., the
operating voltage changes depending on signal level. This improves efficiency as the power
amplifier gives off substantially less heat. The circuit is completely balanced with a feedback
of only 20 dB, resulting in a very fast amplifier with only slight distortion. In particular, the
rough, unpleasant sound associated with TIM distortion is suppressed. Of course the
amplifiers feature all of the standard protection circuits including a clip limiter.

WARRANTY

Adam Hall Limited warrants this equipment to be free of all provable defects in material and workmanship
for a period of twenty-four (24) months from purchase provided that it is used as intended. This warranty
does not cover any damage caused by incorrect or improper operation. Third-party tampering will
invalidate any and all warranty claims. As a rule, the warranty comprises free repair of the equipment.
There is only a claim to an equivalent substitute if the equipment cannot be repaired.

The power amplifiers in the PA series were manufactured in compliance with the valid European directives on
electromagnetic compatibility. They comply with Directives 89/336/EEC and 92/31/EEC as well as the Low­Voltage Directives 73/23/EEC and 93/68/EEC.

©ADAM HALL LTD Southend-on-Sea, Essex SS2 5RU, England www.adamhall.co.uk

Design

Graded according to varying levels of performance, LD Systems PA amplifiers offer you a range from 2 x 200
W (8 ohms, 320 into 4 ohms) to 2 x 1500 W into 2 ohms (PA1600X). All of the units are housed in a 19” chassis
that occupies two height units (2U). A 5mm thick aluminum front panel in conjunction with the rugged steel
chassis and rear fastening points provides above average protection for the electronics and ensures
permanently safe operation. The internal structure of the power amplifiers is based on a modular principle.
Functional groups such as power supply and right and left channel with corresponding heat sinks are
independent units and can simply be replaced by a technician if service is required. Each side of the power
amplifier has its own fan, the speed of the fans is automatically controlled according to temperature. The
electrical layout, i.e., the circuitry principle of the power amplifier, is strictly balanced and fully
complementary.

Setup

The power amplifier is relatively easy to install. It is intended for installation in standard 19” racks. The
minimum installation depth behind the front plate is 38 cm (15"); including the connectors, 43-45 cm (17”- 18")
of space should be available. In addition to front mounting, it is absolutely advisable to fasten down the unit
using the screw holes provided for this purpose in the sidepieces on the rear panel. The rack used must provide
sufficient ventilation, e.g., removable rear cover, ventilation grille, etc. The ambient temperature at the place
of use should not exceed 55°C. If the power amplifier is to be operated in a rack that is closed at the rear, then
a minimum distance of 10cm to the rear wall must be maintained so that the flow of air is not impeded. If the
power amplifier begins to overheat for lack of air circulation, the thermal protection switch shuts it down until
it cools off by a certain amount. The protection switch resets automatically, i.e., once an appropriately lower
temperature is reached, the power amplifier automatically switches on again.

Power Supply

The power amplifier connects to the power supply system via a cable with a safety plug that is permanently
attached to the unit. The power amplifier fulfills the requirements of Protection Class 1 and thus may only be
operated when connected to a properly installed earthed-contact socket. The intended operating voltage is
nominal 230 VAC at 13A maximum.