I have got a new transformer i want to connect it to my subwoofer,but i have measure it before connect it to 220vac and it produce 16.5V-0-16.5V ,bt iwant to optimize it so that to produce 14.2v-0-14.2v output that resemble to those needed by the circuit so how can i do so that when i measure output voltage i get 14.2v-0-14.2v pliz help me

 

Are you absolutely certain you need to change the output? Is that transformer sold as a replacement for the original? What is the output voltage when the transformer is in circuit and under load?

 

No easy way short of a variac.