Specifications

(8) Indicators

In addition to the limit indicators described above, the APL-220, -500, and

-800 have a green LED labeled Power that indicates AC mains power is

applied and the power supplies are functioning properly. A red LED labeled

Protect is also provided to indicate that the amplifier has gone into the pro-

tect mode. Protect mode occurs under the following conditions:

(a) The amplifier has exceeded its maximum safe operating temperature (the

amplifier will automatically reset after cooling down).

(b) The amplifier has failed and is outputting DC voltages that could damage

the driver(s), or DC is present upstream of the amplifier due to component

failure in the processor.

output voltage.

(d) The amplifier has failed to pass its automatic internal start-up test.

If conditions b, c, or d are encountered, the amplifier will latch in the Protect

mode until the power is cycled to force a reset. However, if the fault condi-

tion has not been repaired upon power-up, the amplifier will again enter into

the Protect mode.

NOTE: If the heat sink is cool to the touch and the Protect LED is illuminat-

ed, the cause is most likely due to a driver failure.

NOTE: On early models the Protect LED may be labeled Temp, however all

functions are exactly the same as described above.

(1) Overview

Despite their small size, the APL-220, -500, and -800 are powerful pieces of

equipment that can be utilized in an extremely wide range of applications.

They are highly effective when single units or pairs are deployed as a basic PA

system for live music, track playback, and the spoken word. And because they

are designed to be modules in a larger system, they can be arrayed with addi-

tional units to form a large, concert-class system.

The three models array smoothly in both the vertical axis and the horizon-

tal axis. We call this bi-planar arrayability and it means that the frequency

response, phase response, and distortion characteristics are all preserved,

whether the system is built up of five enclosures or fifty.

An example of a typical array is shown in Figure 4.

Using the

APL-220, -500,

and -800