Quantum QL812SP, Owner'S Manual

26

ENGLISH

The input sensitivity of the High Level Input is set to 15 ~ 45 V ex factory. If necessary, the input sensitivity for 

each input channel can be changed to 2 ~ 15 V. To do this, you have to remove the respective jumper inside 

the housing on the circuit board. Proceed as follows:

HIGH LEVEL INPUT SENSITIVITY

IN CH7

IN CH8

IN CH5

IN CH6

IN CH3

IN CH4

IN CH1

IN CH2

First disconnect the device from the power supply. Then remove the housing cover and locate the six jumpers 

on the circuit board. These are located below the audio inputs.

Then carefully remove the jumper on the desired input channel to set it to an input sensitivity of 

„2 ~ 15 V”

. 

Use suitable pliers for this.

You can determine the correct jumper position for your application with the following procedure:

•  Turn the input control 

„LEVEL INPUT“

 of the respective channel pair group on the device to 

„MIN“

. Then set 

the volume level of the outputs to around “75%” in the DSP software or DSP app. If you then hear distortions 

from the loudspeakers, the factory setting 

„15 ~ 45 V“

 is suitable in this case. Then turn the „LEVEL INPUT“ 

controller back a bit until the distortions are no longer audible.

•  If no distortion can be heard from the loudspeakers, you can remove the jumpers of the respective channel 

pair group in order to achieve a higher power reserve with the 

„2 ~ 15 V”

 setting. Then gradually increase 

the input sensitivity of the respective channel pair group using the 

„LEVEL INPUT“

 controller until slight 

distortions can be heard. Then turn the controller back a bit until they are no longer audible.

Note:

 Depending on the structure of the sound system, the signal outputs can be operated with different output 

voltages. Use a multimeter to check the resistance of the connected speakers. If the resistance is over 5 ohms, 

the associated high-level input should be operated with a higher voltage, i.e. 

„15 ~ 45 V“

. If the resistance is 

around 4 ohms or less, the associated high-level input should be operated with a lower voltage, i.e. 

„2 ~ 15 V”

.