PDF Version

Dear sirs.

I have Free pdf Architect I activated create module. I need to create pdf, version 1.6 (Acrobat 7.x). But files are created in PDF Version 1.7(Acrobat 8.X). How can I change the setting. 
Also I have PDF Creater, but using it, I can create PDF just untill PDF Version 1.5 (Acrobat 6.X)