power to more than 1 effect in a box

[burningwater]

I want to make a box with 2 or 3 effects in it. Not sure if I need a 9v for each one or can I run them off the same 9v. My question is if I run both off one 9v battery will each circuit be getting less current, even if Im not using them at the same time?

Also will I need to have 2 separate dc jacks to use with my pedal power or can I just have one. I read somewhere that a wall wart transformer will supply several 9v pedals with current as long as you dont exceed the MA rating.

Thanks

[boogietube]

Here's a 2 in one wiring diagram:

http://www.generalguitargadgets.com/pdf/two_in_one_wiring.pdf

[petemoore]

want to make a box with 2 or 3 effects in it. Not sure if I need a 9v for each one or can I run them off the same 9v.
  Paralleling Neg Gnd CCt.s is done in...BMP, BSIAB, Jfet amp sims etc.
  Yer WW probably provides much more current that you'll draw, you can figure this out, add the current draw of each pedal and compare it to the Ma rating of the WW.
My question is if I run both off one 9v battery will each circuit be getting less current, even if Im not using them at the same time?
  Not noticably until the battery voltage starts dropping as it loses charge, which'd probably be a good while...depends on the current draw of course.