Ernest wrote:


> >
> >         Clip one of the wires to the speaker and install a variable
> resistor.
> 
> You need a volume control switch. Wire it so that it lies between the
> Motherboard and the speaker.
> 
>                      -(neg)   ____________ (speaker)
> (Motherboard)                                          |
>                     +(pos)  _______ (volume control switch)
> 
> 

so, it's a variable resistor and that's all!
Thank you very much, I'll try.

Igor