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turn off, check your speakers to verify that they are operating
properly. If all other potential sources of trouble check out
properly, contact Knoll for further assistance.
Knoll Systems service information
The 21K amplifier does not contain any user serviceable parts
inside. If you suspect a problem that may require servicing,
contact us at
www.knollsystems.com/contact.html, or by phone
at 800 566-5579. It is extremely important that only an
authorized service dealer make any repairs. This will ensure
proper service and preserve the protection of your warranty.
Keep your receipt in a safe place so that it will be available to
verify the purchase date, should you experience a problem
covered by Knoll System’s warranty.
Care, maintenance, and cleaning
When the 21k amp becomes dirty, wipe it with a clean, dry, soft
cloth. If necessary, first wipe the surface with a slightly
dampened soft cloth with mild soapy water, then with a fresh
cloth dampened with clean water. Wipe dry immediately with a
dry cloth. NEVER use benzene, thinner, alcohol, or any other
volatile cleaning agent. Do not use abrasive cleaners, as they
will damage the finish of the metal parts. Avoid spraying
insecticide, waxes, polishing agents, or any aerosol product near
the 21K.
21k Automatic on
Make certain that the connection to the controlling device is
correct. Whenever the controlling device is turned on, the
amplifier will automatically turn on after a short pause. This
pause is intentional and it protects your speakers from damage
while the amplifier stabilizes. You may also hear a relay click
during start up. This is also normal.
To turn off your amplifier, just turn off the device feeding the
amplifier its audio signals. The amplifier will automatically turn
off, which takes a few moments.
Gain controls
Level adjustments may be made at the rear of the amplifier.
The circuitry in your new amplifier may be different from your
previous one. Check the output levels to make sure that the
control device amplifier and speakers are properly matched.
Adjust these controls carefully as they operate in conjunction
with the volume control(s) on your source device. Turn down
the volume control(s) on the source device before adjusting the
controls on the amplifier.
AC line connector and power cord
Warning: Under no circumstances should the round third prong on the plug
be cut, bent or in any other way defeated as this may result in severe shock.
Always turn off the amplifier and unplug the power cord before making any
electrical connections.
Protection circuitry
Your Knoll amplifier uses an advanced protection circuit. The
output will be cut off if excessive low frequency (below 10 Hz) is
present, if the amp over heats or has excessive current
demands. The amplifier will begin to operate normally after the
over heating or excessive low frequency. Should this occur,
check all speaker wire connections, both at the speaker
terminals on the back of the amplifier to make certain that none
of the strands from any channel touch another channel, and that
none of the strands from a “positive” terminal touch strands
from a “negative” terminal. Even a few stray wires can cause
the amplifier to go into the protection mode. After checking all
speaker connections, turn the unit back on. If it continues to