adaptors instead of battery

[good mourning]

Does anybody know how to cancel the tremendous hum
caused by using 9V adaptors instead of 9V battery?
I use adaptors for every DOD, Dunlop, Boss and more...
effect and for my tube screamer with electronic bypass
without hearing fastidious noises.
I can't use battery 'cause effects are arranged in a
pedalboard (it's inconvenient replacing them).
For some effect that i built (lofo mofo and sonic distortion)
the AC/DC operation causes a lot of buzz,
I tried stabilized adaptors but they are very expensive!
Is there a circuit or another operation to reduce
drasticly noise without using batteries?
:?:

[MartyMart]

Are you using an expensive regulated power supply, or a cheap and nasty one ??
I dont get any "hum" when I use my "Boss PSA" or my "One Spot" PSU, only with "cheap" switchable units from a hardware store.
Those things just are not up to it !

Marty.

[good mourning]

thanks Marty
mine are cheap! you are right!
so with one of yours i won't hear hums...
how can i choose adaptors?
i use those with these features:
230V - 50Hz input
3-12VCC outputs
500mA,
11 - 12.5 W
what do i have to buy? what features?

[MartyMart]

You just have to get a good quality "Regulated" 9v at least 400ma, we find them here at "RS" or maplins, they cost about £15 upwards, anything cheaper is no use, or get a Boss PSA 220,  these are a bit more but are good quality PSU's.
The "One spot" is also good and is rated at 1000ma, it will run quite a few pedals !!

Marty.

[Hal]

you can make yourself a nice filter/regulated unit for less.  I don't know about the european surpluss shops, but the American ones always have adapters pretty cheap.  So get, for like $2, a 12v DC adapter, run it through a big capacitor, then a voltage regulator, then a medium (100uf) and small (100pf) capacitor, and you're set!