SIGNAL Present Indicator

This LED illuminates whenever there is a signal present at the MAIN INPUT connector on the rear panel. It senses the signal just after the Level control, so if the Level control is turned down, the SIGNAL Present indicator turns off.

LIMIT Indicator

The SA1521 has a built-in limiter that prevents the amplifier outputs from clipping or overdriving the transducers. The LIMIT indicator lights when the limiter is activated. It’s okay for the LIMIT indicator to blink occasionally, but if it blinks frequently or lights continuously, turn down the level control until the LIMIT indicator only blinks occasionally.

THERMAL Indicator

There is also a thermal protection circuit that monitors the internal temperature of

the amplifiers and heatsink. If the temperature should exceed a safe operating level, this indicator lights and the signal is muted to allow the amplifiers to cool. When the temperature cools to a safe level once again, the thermal protection circuit deactivates and normal operation continues.

Note: Activation of the thermal protection circuit is an indication that you should take steps to avoid continued thermal problems. See “Thermal Considerations” on page 6.

Power Switch

Use this switch to turn the SA1521 on and off. Make sure the level control is turned down before you turn it on.

AC Receptacle

This is where you connect the AC linecord to provide AC power for the built-in power am- plifiers. Plug the linecord into an AC socket properly configured for your particular model.

HOOKUP DIAGRAM

DAISY-CHAINING MULTIPLE SA1521s

To Next

 

 

To Next

Speaker

 

 

Speaker

SA1521

SA1521

SA1521

SA1521

 

Left

Right

 

 

Line level

Line level

 

 

Output

Output

 

 

Mixer or

 

 

 

Preamplifier

 

 

CONNECTIONS

The SA1521 has one female XLR input that accepts a balanced line-level signal. When connecting a balanced signal, be sure it’s wired per AES (Audio Engineering So- ciety) standards:

 

XLR

 

 

 

 

Hot (+)

Pin 2

 

 

 

 

 

 

 

 

Cold (–)

Pin 3

 

 

 

 

Shield (Ground)

Pin 1

Balanced XLR Connectors

 

5