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21K Stereo amplifier specifications  

 

Inputs:  

 

Gold RCA jacks with adjustable gain 

Input impedance:  

50k ohms 

Outputs:  

 

5 way gold insulated binding posts 

Output power:  

90 watts RMS per channel (8 ohms) 

Ideal impedance:  

4 – 8 ohms 

Frequency response: 10 Hz – 40 kHz +/- 1dB 
S/N ratio:  

 

Over 106 dB A weighted (90 watts) 

THD distortion:  

Less than 0.1% 20 Hz to 20 kHz 

IMD distortion:  

Less than 0.01% 60 Hz 7 kHz 4:1 (SMPTE) 

Dimensions:    

17” x 3.5” x 11.5” (432 x 89 x 292 mm)  

Fan noise:  

 

No fan needed 

Power:  

 

Maximum 320 watts at 117 VAC 60 Hz 

Weight:  

 

20 lbs   

Construction:           Steel chassis, powder coated; glass epoxy 
                              printed circuit boards 
Rack version:           21k-Rack 

 

 
 
 

 

 

 

Three Year Limited Warranty 

Knoll Systems warrants 21K amplifiers sold in the USA or Canada by authorized 
Knoll dealers to be free from defects in materials and workmanship. This 
warranty extends for three full years from the date of purchase by the 
consumer. Any products returned freight prepaid to Knoll Systems and found to 
be defective by Knoll Systems within the warranty period will be repaired or 
replaced at Knoll Systems option, at no charge. Knoll Systems will not be 
responsible for the actual cost of installation or removal of the product, nor for 
any consequential or incidental damages. Some states do not allow the 
exclusion or limitation of incidental or consequential damages, so the above 
limitation or exclusion may not apply to you. This warranty gives you specific 
legal rights. You may have additional rights, which vary from state-to-state. 
Knoll products sold outside of the USA and Canada may be covered by 
warranties provided by an authorized Knoll distributor. Please contact the 
distributor in the country that the Knoll product was purchased. 

 
Knoll Systems

   www.knollsystems.com   

145 Tyee Drive Point Roberts, WA 98281 
12140 Horseshoe Way Richmond BC V7A 4V5 
Telephone (604) 272 4555, Fax (604) 272 5595

 

Made in Canada

, © 2005, All Rights Reserved 

                    

 

 

21K 

 

Stereo Amplifier  
Installation Instructions 

v1.1

 

 

 

 
Caution:

 To reduce the risk of electrical shock, do not remove 

the cover (or back). No user serviceable parts inside. Refer to 
qualified service personnel.  
 

Warning:

 To reduce the risk of fire or electric shock, do not 

expose this appliance to rain or moisture.  

 
The lightning flash with arrowhead, within an 
equilateral triangle, is intended to alert the user to the 
presence of uninsulated “dangerous voltage” within 

the products that may be of sufficient magnitude to constitute a 
risk of electrical shock to persons. 

 
The exclamation point within an equilateral triangle is 
intended to alert the user to the presence of 
important operation maintenance (servicing) 

instructions in the literature accompanying the appliance. 
 

 
 
 
 
 
 
 
 
 
 

Summary of Contents for 21K

Page 1: ...ome states do not allow the exclusion or limitation of incidental or consequential damages so the above limitation or exclusion may not apply to you This warranty gives you specific legal rights You may have additional rights which vary from state to state Knoll products sold outside of the USA and Canada may be covered by warranties provided by an authorized Knoll distributor Please contact the d...

Page 2: ...e location on the apparatus and the function of the switch shall be described and the switch shall remain readily operable 18 A push button is used to turn the power off and on 19 A LED is used to show when the apparatus is powered on CAUTION These servicing instructions are for use by qualified service personnel only To reduce the risk of electric shock do not perform any servicing other than tha...

Page 3: ...e Our engineers and designers spent years of pain staking research and testing to perfect the sound quality We hope you will appreciate this effort and enjoy the amp Unpacking The carton and packing materials used in shipping your new amplifier were specially designed to protect it from the shock and vibration of shipping We suggest that you save the carton and packing materials to use if you move...

Page 4: ...r all cables are responsive If the hum disappears when the input cables are disconnected but returns after the cables are changed and the system reconnected your source device may be causing the problem Troubleshooting Your Knoll amplifier is designed from trouble free operation If you follow the instructions in this manual you should enjoy many years of high quality listening enjoyment However as...

Page 5: ...rt the plug into the jack Loose connections can cause intermittent sound and may damage your speakers Some quality RCA plugs may be very tight and it is important to secure a proper connection between the interconnection cable and the input jack Speaker connections To ensure that the high quality signals produced by your amplifier are carried to your speakers without loss of clarity or resolution ...

Page 6: ...izes 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 l...

Page 7: ...e to the matching terminal on the speaker The positive or red wire should be connected to the matching terminal on the speaker Note While most speaker manufacturers follow industry convention of using red terminals for positive connections and black terminals for negative some manufacturers may vary from this configuration To ensure proper phase connections and optimal performance consult the iden...

Page 8: ...kers 21k Manual on Press the 21k front power switch to the on position There will be a short pause from the time the power is turned on until power is applied to the speakers This is intentional and protects your speakers from damage while the amplifier stabilizes The red protect lamp will glow and when the amp is ready a blue light will switch on To turn the unit off press the power button again ...

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