Questions on K2572

Kits Audio Hi Fi Projects
1

Hallo,

Hallo,

In order to connect an MP3 player and a car radio using the AUX input, I bought a K2572 kit and assembled it carefully. Before putting the K2572 between the MP3 player and the car radio I did some measurements.

The resistance I found, without any connection, between both inputs and earth is endless, which is OK , I think.

However, when I connect the power supply, I find a voltage of 7V between each open input and earth.

Does somebody know whether this is normal and that this voltage will not destroy the output of the MP3 player, when this device is connected?

Thanks in advance for some information on this subject.

Harry

2

This is normal.
Due to the high impedance of the multimeter, the input cap remains discharged or will charge very slowly, so you measure half the supply voltage.
Once the MP3 player is connected, it’s output impedance will allow the cap to charge.