transformer?
I'm pretty sure you mean a transformer, not a transformator - whatever that is.
1200 to 8 ohm, means that you'll want to transfer the impedance from 1.2k to 8 ohms. That gives us a ratio of 1/150, and since secondary to primary impedances tranfer with inverse square proportions you'll want a ratio of sqrt(150), which is 12.24.
What you need is a transformer of turns ratio of 1:12, which will convert your 1200 Ohm impedance into 8.3 Ohm impedance. So when you go to the store (or order from catalog), ask for that. If you can't find that particular ratio then try substituting. Use the following formula to calculate your resulting resistance:
R(converted)=1200*(1:n)^2
where n is your turns ratio. When you assemble the circuit make sure you connect primary winding (the one with 1 winding) to the source, and secondary to your impedance (1200Ohms)
Hope this helps.