http://www.uploadarchief.net/files/download/vu meter toerenteller.jpg
Heyy. Im new to electronics. I have built 10 led vu meter and want to build 20 led meter^^.But i dont understand one thing- why theese resistors on both sides are connected seperately. I mean why cant 1k and 3,9k resistors be connected like one 4,9k? isnt thats the same?

 

Hello zazas321

No, definitely is not the same as putting a resistance of 4.9K instead of two, one of 1K and another 3,9K.
These two resistors form a voltage divider.
With a single resistor how would you do ??

This voltage divider is to program the IC 'Telling'
what level of input voltage at PIN 5 turn ON the LED connected to PIN 1.
And
what level of input voltage at PIN 5 turn ON the LED connected to PIN 10.
It is to the measurement range.

Keep an eye to the attached PDF document.

 

but those resistors are connected in series to each other arent they?

 

The two resistors are to set the ref hi voltage and led current, see the datasheet...

 

but those resistors are connected in series to each other arent they?

Yes, but you're using a voltage from the divider.