User's Manual

The Servo Series Protection Circuitry

As noted in the “Guided Tour” section of this manual, the Servo Series front-panel

Protection LED indicates the activity of the relay speaker connection circuitry. When

the Protection LED is lit, this circuitry is active, and all connected speakers are muted

(provided with no signal), thus protecting them and preventing any audible “thump”

from occurring.

The following conditions will cause the Protection LED to go on:

• Initial power-up:

For approximately five seconds after initial power-up, the protec-

tion circuitry is activated and the speaker outputs are muted. If everything is operat-

ing normally, you will hear an audible click at the conclusion of this brief period, as

the protection circuitry is deactivated and the Servo Series begins delivering signal to

connected speakers (at which point you’ll hear a click). It is normal for the Protection

LED to fade gradually after the amplifier is powered off.

•

Overheating:

A temperature sensing device in the Servo Series will cause the protec-

tion circuitry to be activated (and the Protection LED to go on) whenever the operat-

ing temperature of the unit rises above a safe level. To guard against this problem,

make sure the Servo Series receives adequate ventilation on all sides and that both

the front and rear panels are unobstructed.

• Severe overcurrent conditions:

This occurs whenever the signal being output from the

Servo Series rises to a level above 20% THD (Total Harmonic Distortion).

• Shorted speaker cables:

This will occur if, due to faulty wiring, the hot and ground sig-

nals being output by the Servo Series are shorted to one another.

• Output impedance drops below 4 ohms

: This can occur if the Servo Series is connect-

ed to inappropriate speaker systems (see the “Setting Up and Using Your Servo Series”

section on page 6 in this manual for more information).

• DC voltage detected at speaker output

: The most likely cause of this is an internal fail-

ure.

In general, any time the Protection LED lights up (other than during the approxi-

mately five seconds following initial power-up), there is reason to be concerned. If this

occurs, turn the Servo Series off immediately and carefully check all wiring and exter-

nal devices in order to locate and correct the condition that caused the LED to light up

in the first place.

For further assistance, contact your local Samson dealer. If purchased in the United

States, you can call Samson Technical Support (1-800-372-6766) between 9 AM and 5

PM EST.

WARNING: If the Protection LED fails to go out (and you fail to hear the accom-

panying audible click) approximately five seconds after power-up, turn the

Servo Series off immediately and check all external devices and wiring for pos-

sible shorts or other defects.