Hi everybody,
I want to feed my stompbox with AC power supplier converted to 9 volts DC.
What should be the ampere rating?
Thanks in advance.
Yves
Depends what the current drain of your pedal is :D
I think the boss ones are rated at 200mA, but anything that is more than the current drain will do. I used to use a 300mA to power 5 pedals with a daisy chain before I melted it by running 15 pedals off it :twisted: Now I'm set back into the stoneage with my batteries... :roll:
Go out and buy a powersupply that is rated at about twice the current drain of your pedal.
By far the best way to go IMHO is to get a good sized adapter, like 9 volts @ 1 amp. Many of these will put out a few more volts than 9 when a small current is being drawn so you should check with a meter.
If you have 3 or more volts left over (not too uncommon), add a regulator like a 7809 with a couple of caps to give yourself a nice regulated supply. It's probably better to start with a 12V @ 750mA or 1 Amp adapter and then regulate down from there. Use a good sized capacitor on the output and bypass that with a smaller film cap (try a 1000uF electrolytic in parallel with a 0.1uF film). When you have a big cap after the regulator, you also need to add a power diode (1N4001 works fine) across the input and output of the regulator. Connect the cathode (the side with the band) to the regulator input and the anode to the output. That will stop the cap from reverse discharging through the regulator when you turn the power off.
Take care,
-Peter