PROBLEM: No Sound
• Check both ends of the AC line cord for proper connection. Both ends should be fully seated in their connectors.
• Check that the AC outlet works by plugging in a known-good device or by testing with a voltmeter. If too many
amplifiers are used on one outlet, the building’s circuit breaker may trip and shut off power. If this is the case,
unplug some of the amplifiers from the outlet, reset the building’s breaker and try again. For the other amps,
use an outlet that is connected to another circuit breaker to distribute the load current.
• An amplifier which keeps tripping the AC circuit breaker may have a serious internal fault. Turn it off, remove
AC power, and have the amplifier serviced by a qualified technician.
PROBLEM: HISS
• Unplug the input cables to the amplifier. If the hiss goes away, then the problem is with the equipment or
cables leading to the amplifier.
• If the hiss is present with no audio input cables connected, check that the AC line cord is properly grounded
at its connection to the line. If the ground connection is OK and the hiss continues with no input cables
connected, then the amplifier requires servicing.
• To keep the normal noise floor low, operate the primary signal source at full level, without clipping, and avoid
boosting the signal further between the source and the amplifier.
PROBLEM: HUM
• Use a common AC ground connection for all audio equipment.
• Check the input cables for broken ground (shield) connection.
• Use balanced connections for the entire signal chain.
• The design of the amplifier eliminates internal hum fields, but external transformers or other magnetic devices
may cause hum. Move cabling and signal sources to identify “hot spots” in the system; then avoid those spots.
Cables with faulty shielding are a common entry point for hum. Use top quality cabling. Another common
source of magnetic fields are “wall warts” or pluggable transformers; keep input wiring away from them
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Troubleshooting
