Krell Full Power Balanced X Series Power Amplifiers
19
Amplifier Troubleshooting
AC grounding becomes critical when connecting high performance
audio components. When you mix and match audio components,
each with its own ground potential, a low frequency hum may occur
in one or both loudspeakers. This often occurs when introducing a
new component into a system.
If a low frequency hum emanates from the loudspeakers when you
place the Full Power Balanced amplifier into the system, follow
these simple troubleshooting steps:
During these steps, the back panel power breaker switch remains in the
on position.
1.
Check all input and output connections, making sure they are of
sound construction. With the amplifier in stand-by mode,
remove the interconnect cables, then press the front panel
power button. If the hum disappears, press the power button to
return to stand-by mode, and reinsert one of the interconnect
cables. Press the power button again. If the hum reappears
with one or both interconnects inserted, there may be a defec-
tive cable. Have the interconnect cables checked before pro-
ceeding.
2.
If the interconnect cables are sound, you may be experiencing
a ground loop. This can often be easily eliminated. Please con-
tact your authorized Krell dealer, distributor, or Krell for sugges-
tions on how to solve this problem.
Full Power Balanced amplifiers are protected by a series of nonin-
trusive circuits that constantly evaluate the amplifier’s operation.
This circuitry protects against damaging DC input or output and
short circuits, see also
DC Protection Circuitry,
on page 14, and
monitors regulator operation, ensuring constant voltage to the out-
put stage. The protection circuitry in a Full Power Balanced amplifi-
er is designed to prevent damage to the amplifiers or loudspeakers
caused by other defective components, faulty wiring, system mis-
handling, or amplifier failure.
In addition, when a Full Power Balanced amplifier’s DC protection
circuitry senses a problem within the system, it identifies, then indi-
cates the problem by illuminating the front panel blue LEDs, as
described in the following table.
The Krell CAST LED illuminates only if a Krell CAST input is being used.
There are no output fuses in Full Power Balanced amplifiers.
HOW TO
TROUBLESHOOT
SYSTEM NOISE
HOW TO EVALUATE
AMPLIFIER OPERATION
Notes
Note