When decoupling power supplies from a single source for multi-fx, regulators?

Started by guitylerham, March 20, 2012, 09:39:49 PM

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guitylerham

Hey! I'm now designing the power section for my multipedal and need to know the best way to decouple! I'm using a weber transformer with eight 11vac secondaries. Some pedals will get their own isolated secondary while some pedals will share a secondary. With those pedals, I plan to decouple using a resistor and capacitor on the power lines (lowpass filter?). Would it be beneficial at all to use regulators for each supply too? So my 11vac secondary gets rectified, then to the big 1000uf cap, and then from there branches off to say four 9v regulators that then get more filtering and decoupling and then follow on to their respective effects. What say you all? Are there certain components that need to be as close as physically possible to other parts in a power section?


Processaurus

You don't need multiple regulators to branch power off to your effects.  You can fan out your regulated power to them directly, or use an RC combo per effect to isolate them if needed, say a 100 ohm resistor in series, then a 100uF cap to ground.

With your multiple transformer secondaries, you might want to give any digital pedals, as well as anything with an LFO or clock or logic or comparator action their own isolated secondary and regulator.  Most analog effects like distortion don't put much noise on the power lines however, so those can share power rails. 

If you put a header on the power connections to each effect, it will be easy to connect and disconnect power in case you want to see if things are quieter with different power distribution.  With power headers, if they can be put on backwards, it is a good idea to use a 3 pin header, with ground on both outside pins and power in the middle, that way if it goes on backwards the polarity isn't reversed.

guitylerham

Good deal! That simplifies everything a bit. I'm pretty excited with my latest decision on power assignment as it's been a long refinement process.

Eight 300mA 11vac secondaries:
1 - input buffer/splitter (splits off to tuner) , Ross comp, TS-5, Tube Sound Fuzz, Dist+, Boost, Peppermill (for after the Leslie sim)
2 - EA Tremelo
3 - CX-3 Leslie Simulator
4 - Digi-Log Reverb
5 - Digital strobe Tuner (not in audio path but gets its own secondary to be safe)
6 - Deluxe memory man (two 9vdc stacked for 18vdc)
7 - Deluxe memory man (two 9vdc stacked for 18vdc)
8 - Auxillary 9vdc out for external effects

One 1A 9vac secondary:
Power to all LED's with adjustable brightness knob!

My next step is to build the supply, hook it up to all the effects and see which ones work!!

Thanks, Processaurus!