CAT Problem Solving and Troubleshooting 2

Question 1

A powered loudspeaker produces a loud 60 Hz hum even when no signal is connected. What is the most likely cause?

Accepted Answer

Ground loop through the AC power connection

Answer

A 60 Hz hum present with no signal input typically indicates a ground loop introduced through the AC power path.

Question 2

During a live event, one side of a stereo mix drops to silence intermittently. The mixing console meters show signal on both channels. Where should you check first?

Accepted Answer

The cable run between the console and the amplifier

Answer

Intermittent dropout on one channel with confirmed console output points to a failing cable or connector in the signal path between the console and amp.

Question 3

An amplifier's clip indicator lights continuously at moderate gain settings with a clean input signal. What is the most probable cause?

Accepted Answer

The input sensitivity is set too high

Answer

Continuous clipping at moderate volume with a clean input usually means the input sensitivity (gain) trim is set too high, driving the amp into saturation.

Question 4

You measure 0 VDC on the output of a Class-D amplifier while the input signal is present and the power LED is on. What is the best next diagnostic step?

Accepted Answer

Check the protection relay and fault indicator

Answer

Class-D amplifiers have protection relays that disconnect the output on fault conditions; checking the relay and fault LED is the correct first step.

Question 5

A condenser microphone produces distorted audio only at high sound pressure levels. The most likely fault is:

Accepted Answer

Overloaded mic preamplifier input

Answer

Distortion that appears only at high SPL is a classic symptom of a mic preamp input stage being driven beyond its headroom.

(CAT) Commercial Audio Technician Practice Test

(CAT) Commercial Audio Technician Practice Test

CAT Problem Solving and Troubleshooting 2