Power issues.

[dubiousss]

Ok so walwarts just dont work at all, but i found this power supply that works, it consists of a transformer that gives 30v dc, W005M 7948, 1000uF cap, .1uF cap, and a 7812C.
I think it used to give 12v but now it give about 16-18V, so on all my pedals I put a lm7809+cap. But ive noticed on my breadboard that even with a new 7809 the voltage only drop from 18 to 12v, whats going on!?

Also I read the geofex power stuff but even giving lots of caps before and after transistors doesnt get rid of the ripple.

Also I'm making a +12-12+15-15 power supply from 9v for the meastro ring mod and was wondering if it was possible to get +18-18 from one 7660 chip(like the max4088) i can make +18 and -9 with one then -18 on the second  but was wondering if i could do it with just one chip?

[dubiousss]

Ok scrap that first question, my multimeter is just low on battery i think, i just measured a 9v battery as 12v :\