Precautions: The amplifier is a wideband design with substantial power output capability. Certain precautions must be taken to ensure proper operation:
1.Never expose the unit to moisture.
2.Never plug an input cable into the amplifier while the amplifier is turned on.
3.Never apply the “thumb test” (touching the “hot” lead of the input cable with your finger) to the tip of the input cable or input jack of the amplifier. RF rectification and/or hum will be created and could cause damage to the loudspeakers. Knoll will not be responsible for damage to the loudspeakers due to improper use of the equipment.
4.Under no circumstances should the output terminals of the amplifier be
5.Avoid restricting the airflow around the unit. Good airflow is necessary to help ensure proper operation.
6.Be sure that the loudspeakers connected can handle the output power of the amplifier at the loudspeakers rated impedance. The warranty on the amplifier does not cover damage to loudspeakers that have inadequate power handling capabilities.
7.Do not stack other system components or any other materials directly on top of the unit. The heat dissipating system of the amplifier depends on
SAFETY INSTRUCTIONS:
WARNING: TO REDUCE THE RISK OF FIRE OR ELECTRIC SHOCK, DO NOT EXPOSE THIS UNIT TO RAIN OR MOISTURE.
Read all the safety and operating instructions before connecting or using this unit. All warnings on the unit and in this operating manual should be adhered to. All operating and use instructions should be followed.
WARNING: This product contains chemicals, including lead, known to the State of California to cause birth defects or other reproductive harm. Wash hands after handling.
Knoll Systems service information
The MA252 amplifier does not contain any user serviceable parts inside.
If a problem is encountered with the MA252, the most expedient procedure is to locate the problem and if possible repair it before requesting service. Be sure to carefully check other system components such as controllers, CD players, volume controls, wiring, speakers, etc. that may be at fault. If you suspect a problem that may require servicing, contact us at www.knollsystems.com/contact.html, or by phone at
Problem |
| Action |
Power LED does | 1. Check that the MA252 is plugged in. | |
not light - | 2. | Test the AC outlet with a lamp. |
no sound | 3. | If remote on/off is used, check that |
|
| the trigger voltage is at 12 VDC. |
| 4. | Check MA252 power button on (in). |
Sound cuts out | 1. Verify speaker impedance is | |
|
| Changing speakers may be required. |
| 2. | Check if the MA252 feels hot. If it's |
|
| hot increase cooling - see Installation. |
| 3. | If music sense is selected on the rear, the |
music level may be too low to activate and hold the amp on. Turn the source volume up and the MA252 gain controls down to compensate. Connect a 12 VDC trigger (trigger mode) or contact Knoll for information on defeating the music sense mode.
Distorted sound | 1. Turn the volume down. | |
| 2. | Check speakers for damage. |
| 3. | Check inputs for proper levels. MA252 gain |
|
| and source output level may need adjusting. |
| 4. | Speakers may be less than 4 ohms. |
MA252 does | 1. In trigger mode, make sure trigger power is | |
not turn off |
| turning off by removing trigger plug on rear. |
|
| Front panel power switch needs to be OUT. |
| 2. | In music sense mode, turn off source music |
components. If the MA252 doesn’t turn off after about 2 minutes remove the RCA input plugs. If the MA252 turns off, reconnect the RCA plugs and turn down the sensitivity.
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