Krell Industries 400cx Stereo Amplifier User Manual


 
Krell Full Power Balanced X Series Power Amplifiers 19
Q. Should I leave my Full Power Balanced
amplifier on at all times?
A. For maximum amplifier performance, leave
the back panel power breaker switch on at all
times. This places the amplifier in stand-by
mode. Full Power Balanced amplifiers are
designed to be powered on and off from stand-
by, using the front panel power button. This
eliminates cold start degradations. The ampli-
fier will operate at full performance within min-
utes.
Q. When I turn on the amplifier there is a loud
hum through the speakers. What should I do?
A. When a new component is introduced, a low
frequency hum may occur in one or both speak-
ers. Check all input and output connections and
cables, making sure they are of sound con-
struction. See How to Troubleshoot System
Noise, on page 17. If the interconnects and
cables are sound, you may be experiencing a
ground loop. This can often be easily eliminat-
ed. Please contact your authorized Krell dealer,
distributor, or Krell for suggestions on how to
solve this problem.
Q. My system includes multiple pairs of speak-
ers. Can I connect them to my Full Power Bal-
anced amplifiers through a speaker selector
box?
A. No. Most speaker selector boxes use a com-
mon ground scheme. The differential circuitry in
Full Power Balanced amplifiers prohibits the use
of these devices. Do not connect a Full Power
Balanced amplifier to a speaker selector
device that employs a common ground
scheme, as it may short-circuit the amplifier
output.
Q. My speakers have only one pair of binding
posts, but my Full Power Balanced stereo
amplifier has two pairs. Which pair of speaker
binding posts should I use, the upper or the
lower?
A. The upper and lower pair of speaker bind-
ing posts on Full Power Balanced stereo ampli-
fiers are identical. You can use either the upper
or lower pair; they work and sound the same.
See Connecting the Full Power Balanced
Amplifier to Your System, on page 13.
Q. My speakers are rated for 150 Watts. Are
the Full Power Balanced 400cx or 700cx mod-
els too powerful for them?
A. No. A speaker seldom is damaged from
overdriving. More often, damage occurs when
an amplifier that lacks sufficient power is asked
to handle heavy demand situations such as
high playback levels. These amplifiers may
have very high 8 Ohm power ratings, but in
heavy demand situations they can be driven
into clipping (in which DC current goes to
speakers due to loss of amplifier power). Clip-
ping can damage speakers. Avoid damage to
your speakers by reviewing your speakers
specifications and exercise caution in heavy
demand situations.
Questions and Answers