Is this DC offset problem.

[rs1026]

Whenever i switch on my lm3886 based gainclone I observe that the papercone of woofer moves forward and then goes back.This is observed even when I switch of the amp.However instead of switching on the amp if I slowly push the powercord into the mains socket I dont observe this movement of the cone.

Is this a DC offset problem?Is this movement common in gain alone amps?Will this movement damage the drivers in the long run?

 

[Stocker]

This is turn-on thump. solutions are available, do some searching. Usually it is only annoying. If you measure the voltage at your speaker terminals you will be able to tell if you have excessive DC offset.

 

[thomas997]

Do you have an X type cap across your switch? That might help..


If there is a lot of DC offset the cone will move in a direction, and stay in that direction..

As stocker said, get out the multimeter and measure mV at terminals.

 

[jaudio]

Is this DC offset problem

Thomas997 What do you mean X type cap across yours switch

 

[thomas997]

Re: Is this DC offset problem

Thomas997 What do you mean X type cap across yours switch

Something similar to what is shown on this site:

http://www.sector101.fsnet.co.uk/cyberhome/inside/switch/

Across the mains switch.