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
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
