Can I power 3 separate 9v effects with a 27v wall wart

[el badger]

So I competed 2 out of 3 circuits I want to place in one enclosure with 3 bypass switches: guitar line in -> 9v booster circuit -> 9v fuzz circuit -> 9v vacuum tube fuzz circuit -> line out to amp. The enclosure will have 3 foot switches, pots for each circuit, and a toggle (on / on) for each fuzz: clean fuzz / dirty fuzz and warm tube fuzz / tube overdrive / distortion. I tested the first 2 in series and they work like a charm. What I want to avoid if possible, is using 3 separate 9v batteries. So can I power this monstrosity with a single variable voltage wall wart selected to 27 volts? Would it be equally divided among the circuits, or would it fry the first one? Or can it be divided 3 ways through another power circuit of some sort? Any and all advice / direction is helpful from pros and novices alike. I know I can't be the first one to attempt this so if someone knows where a schematic would be, or what to do to power it with one power source would be great. Thanks, you fuzzy bunnies!

[morange]

No. You can use one 9V power supply to power all three, though. You could use a single 9V battery to power all three, just connect them all to the same battery.

The way it works is, connecting more effects to a single 9V source will draw more current from the source, but the voltage will more or less still be 9V for all of them. The voltage doesn't divide between the effects, like you're saying.

[el badger]

Sweet so it is as simple as 3 (+) and 3 (-) wires coming from the same batt or AC input rather than 1 (+) and 1 (-) for one effect?

[morange]

Yep.

You know how people use daisy chains with their One Spot power supply? Same thing. Or, for another example, take a look at an effect schematic with a bunch of stuff connected to the power rails. Each part of the circuit sees the same supply voltage, even though each part draws whatever current it needs from that supply. Like in this rat schematic:
http://www.pisotones.com/RAT/MBC/imgs/RATesquema.jpg
The LM308N and the 2N5458 are both connected to the same 9V supply. But they are really two different circuits: an OP-AMP non-inverting amplifier, and a JFET buffer.

[el badger]

I see.. It would just be (so to speak) one 9v rail and all circuits would plug into it drawing what they need. would i have to link the grounds or would I just keep each circuit separate but for the 9v (+)? Or, now that I think about it each circuit has its own ground and if the 'rail' is treated as individual power supplies then there would be no need to link the grounds. . . linking the grounds might cause problems, right? BTW thank you for your knowledge. I appreciate it very much.

[morange]

Power is a + and - connection, and nothing will draw power unless it's connected to both terminals (forming a circuit, literally, a circle: electricity flows out of one end of the battery, through the components, and back into the other end of the battery). In effects, we call the - ground (well, except for some vintage fuzz circuits with positive ground), and connect everything labeled as ground to it: you know, ground connections in the circuit, as well as the sleeve connection of the input and output jacks. So yeah, all three of your circuits will share the same ground connection and the same positive 9V supply connection. The negative 9V supply connection will be connected to ground, which is the same ground for everything.

[el badger]

excellent.. I figured that would have gone without saying with a circuit needing both (+) and (-) / ground. I was thinking more along the lines of effect ground to effect ground to effect ground then to (-) power supply but if each circuit is 'tapped' into the power supply separately then it must also be tapped into the (-) / ground separately in order for that particular circuit to be complete. Sometimes with older cars i worked on that used generators before alternators the internal electronics would sometimes be in one or several big 'loops' (such as internal lights) that would be connected end to end until eventually the light at the end of the circuit actually connected to the black neg. This excites me so much.

[cloudscapes]

Watch the current if you plan on powering three pedals from a single 9v source. If the sum current of all three pedals is greater than what the adapter is capable of, you'll fry the adapter.

Example. If the adapter is 200mA, and all pedals use up 50mA, you're fine.

[Gigahearts_FX]

Use a 100r resistor from the 9v to each pedal /pcb to get some separation..
Also consider some beefed up power filtering (cap to ground from the the 9v after the 100r, eg 47 or 100uF)

[el badger]

Thank you gents that is very helpful!