noisy effect when uding dc jack

[MmmPedals]

I just built 2 effects in one enclosure. a mini booster then a dod 250. powered with a battery works great, but when i power it with the dc jack the mini booster hums. the dod 250 is quiet. i wired it as follows. 9V from the dc jack separate to each pcb (i.e. not daisy chained). the grounds go from the booster to the input jack and from the dod 250 to the output jack and from bothe the input and output jacks to the dc jack.
Any ideas how to quiet this guy down?

[GibsonGM]

Noisy power supply, sounds like.  I'm sure you've tried the same PS with another pedal, and it is quiet?  You say the circuit(s) work good with a battery - so that is BOTH circuits are quiet and function as they should?
If so, ok, then step 2:
1 idea is to bring BOTH circuit boards' grounds to the same point, like in a star configuration (1 ground point, probably at input jack as you have the booster done).  The DC jack ground will also run over to there, on its own, with the jack isolated from the enclosure (plastic power jacks generally are!).  Output jack grounds back to input jack, too. This will minimize little 'eddy currents' on the ground line, which create noise that couples back into the circuit thru the PS.  Should plan your layouts like that anyway next time, just good practice.
I bet you'll notice a diff. just from moving the booster's gnd over to where the 250 is grounded.  BUT:

If the hum is not gone after this:

You may need additional filtering...try adding a 100R resistor in series with the 9V in (at the DC jack, preferably), followed by a cap to ground.  Try 100u, 470u if necessary.  This may help filter out some of the hum.  Try it out and see what you get!   

[amptramp]

+1 on what GibsonGM was saying.  Star grounding is the only way to avoid ground loop noise via common impedances between the two effects.  The matter of DC wall-wart supplies has come up before, so do not believe that you will get clean power from one.  I am quoting myself here:

I took apart a 6 VDC 700 mA wall wart on one occasion and it was interesting: there was a diode bridge with an unidentified device which is either a small ceramic cap or a varistor across the input, and a 4700 uF 16V electrolytic in series with a 1.0 ohm resistor and the output shunted by 100 K.  The capacitor would be too much of a load for the diode bridge on start-up if the series resistor was not there.  But this causes the 120 Hz fullwave rectified signal to appear at the output.  Do not expect a DC wall wart to be particularly well filtered.  Most people do not use a wall wart with 700 mA capability to power a stompbox with a couple of op amp stages and a few transistors in it.  Most stompboxes only take a few milliamps (or they would not be able to run from a 9 volt battery), so the capacitor value would be decreased proportionally.  I would prefer 9-volt stompboxes to be powered from either an internal battery or a 12 VDC wall wart with regulation of the wall wart input in the stompbox.  Most 9 VDC units will run from 8 volts or less (or the battery would not last long), and most regulators will work with less than a 4 volt dropout voltage (input to output difference below which the regulator IC drops out of regulation), so the regulator could be set to 8 volts for most applications.

You could modify the wall wart to provide the power output directly across the capacitor, making the 1 ohm resistor appear in the supply from the bridge to the cap.  With a full load, this would drop 0.7 volts for a 700 mA device, but with only a few mA the loss would be negligible.  Of course, you would lose all UL/CSA/VDE approval by opening the case, so it's up to you.

[GibsonGM]

Or pick up something like a Godlyke power supply...quick n' dirty, but clean and cheap, regulated (quiet) power.