I also use an acet reg. on a propane tank. I think you need the specific regulator for heavy duty cutting; the flow and pressure of an acet. regulator might be insufficient. For brazing it's fine.

Btw to the OP: the flame temperature is not was is ultimately relevant. The amount of heat is. O/P has 2500 BTU per cuft of gas vs. 1500 for acet. but it uses more oxygen. The flame is also different, it has less heat in the the inner cone. It doesn't fillet braze as nicely but there is less chances of local overheating.