[sdiy] cheap BOSS dc adapter replacement?/switching noise PROBLEM?

[dan snazelle]

This is a 2 part question. (all related to DC 9v power wallwarts)

part one is this-

I want to include a 9v Dc adapter with my effects that will have the Boss style 2.1 mm barrel plug and reverse polarity.
at around 350-500 ma


It needs to be regulated as well as the Boss adapters (or better) and hopefully cost nowhere near as much

any ideas??? i am not sure how good the regulation really is on the Boss adapter anyway and that leads me to question 2


part two is this:

i have been messing around with A circuit that when powered on ITS own by a 9v dc adapter works and sounds fine.
BUT when it is connected (via one of those power splitters for dc adapters) to a 9v dc adapter that is being shared with a few other circuits, it suddenly starts WHINING

(i am assuming this is either switching noise that is coming down the powerline OR a problem with the power being shared)

oddly, lets say there are three circuits.

circuit A and B have no problem sharing power. BUT when circuits A or C or B or C or A, B and C share power, circuit C always gets a whining noise.

adding more large bypass caps HELPED BUT not enough.


is this a common problem? can some circuits just not share power?


or should i look into shielded cable? shielded power cable or audio lines?

any other options?

thanks so much


dan