[J.D.N]

I want to make a switch box so i can switch from my power amp>>speakers to headphone amp>>headphones.

What kind of Switch would be suitable?

 

[JackH]

A double-pole, double throw switch should fit the bill perfectly. Its common terminals get connected to the preamp's output, and one set of the remaining terminals goes to the headphone amp; the other to the power amp. The grounds are all tied together.