I wanted to use a wall wart style mains adaptor to power my pedals as well as a battery, would I have to include any additional circuitry. I have the socket which has a switch built into it, and know how to wire it up, but does the 9v and the ground go straight into the circuit or does there have to be some caps and resistors in there too. To smooth the power and stop noise from the wall wart? may be a didoe to prevent reverse polarity.
Im I on the right lines with this?
The wall-wart should be fine, just as is. Make sure that the polarity is correct. Also check the secondary voltage. there is very little room for error on either of these. Caps across the supply can help smooth it out, but are generally only added as needed (in high gain pedals, for instance).
Oh, and check your grounds. If you are using a negative ground pedal, and put in a non-insulated jack with positive on the outside, it will short.
Other than that, just wire it up like it's a battery.
QuoteTo smooth the power and stop noise from the wall wart?
It depends whether the effect is sensitive to supply hum or not. Circuits with opamps and transistor buffers don't generally need a filter, circuits with MOSFET or BJT gain stages (especially multistage units) will benefit from a filter.
If the wall wart is regulated then it won't have any hum.
Quotemay be a didoe to prevent reverse polarity.
It's desirable put it that way - cheap insurance. Most commercial effects have one.