"Knowledge is Power”… unless we’re putting together our pedalboards and then “power" can be absolutely stupefying. That’s ok though because today we are going to tackle the power issue and boost your knowledge because, of course, “knowledge is key”.
There are a couple things we will need to consider when talking about power: Votage and Current. All of those wonderful little tone-makers on the market today have certain power requirements. These strange ancient markings on the back or bottom of our pedals tell us how to power them correctly so that they will provide hours of endless sonic enjoyment. However, power your pedal wrong and you will just have a cool looking paperweight complete with moving knobs, footswitching action and a humbling story to tell all your gearhead friends.
For our look into power i would like to provide two definitions:
Voltage: Rate at which energy is drawn from a source (the thing that makes a certain amount of "flow" or “transfer”, between the outlet and the pedal, possible). Think of voltage as the gauge of a hose; it connects one side to the other and the bigger the gauge the more voltage.
Current: (this is marked as “ma” or “ma draw”). Think of this as the actual liquid inside our hose; like... uh, maybe we don’t need to turn the water on full blast in order to get the job done. In the case of pedals and power the pedal is the one determining how much Current is sent down the Voltage hose. i.e. 10ma is only going to take 10ma on that 250ma, 9v power supply. (this is why daisy chaining effects, with similar voltages, is possible… as long as you don’t over use your “ma” you’re good). make sense? emPowering isn’t it ;)
There are two ways that we see power used on pedal boards these days: isolated and non-isolated. A non-isolated or “daisy chained” system leaves all your pedals in the same “loop” or power circuit. Non-isolated power is fine as long as all your pedals; require the same power, don’t accumulatively exceed the provided “current”, and that they actually work well with each other. Yes it's true, some pedals, when paired with each other on the same power circuit, can cause weird fizzes and harmonic poo to come through your amplifier; on stage or in the studio this is unacceptable.
Daisy chaining our power is all fine and dandy but there are a few issues that arise: what about this 12v pedal I have? now I have an annoying hum, why? this pedal is 9v but it says it needs + and not - for the ground, what now? (this is a thing called “polarity" and we will get there in a sec). Sure daisy chaining can save room on the outlets just as isolated power can but there are a few reason you will see almost all major artists using isolated power for their rigs. (boards from Metric and The War On Drugs)
Silence is golden - Ok, just to be clear, a daisy chained power system isn’t going to create noise in and of its self. Some pedals, as stated earlier, when linked together on the same “voltage” source can cause some ugly sounds. when you can take those pedals and place them in their own circuit the ugly noise goes away and a smile appears on your face. Isolated power supplies such as the new TrueTone CS7 and CS12 separate each voltage output from the others so that your noise-causing pedal, when bypassed, is also out of the powered loop as well as the audio loop. no longer do you have those annoying pedals mingling together and creating unwanted noise.
One supply to rule them all - Voltage variety is something a lot of us run into; we have that random pedal requiring 18v or 12v but we only want to use one power supply. Having a power supply like the Voodoo Labs ISO5 can provide you with the exact power you need to rock the sox off your fans. Another cool option with differing voltages is the ability to try your analog drive pedals (manufactures like Keeley, Catalinbread and many others allow for a possible voltage range, usually 9-18v, with some of their creations). Running a drive pedal at 12, 15 or even 18v can result in more headroom and a greater overall response; more “amp-like” you could say. Being able to power all your pedals the way you want while still only using one power outlet is about as ideal as sliced bread. it just makes sense.
multiple cabling options = versatility - I remember getting my Empress VMSD. I placed it on my board, went to plug it in and then realized the polarity wasn’t standard. (Wait, what is polarity?) With a direct current or “DC” power circuit, the power signal is sent down two lines, rails, poles, what-have-you; one positive and the other negative. the polarity tells us how to match the ground from our power supply to our pedal so that we don’t fry it. the diagram for polarity looks like this.
Unlike most pedals, the VMSD has a “positive” ground (indicated with a “+” to the center of it’s power requirements). Matching polarity is easy, just make sure the picture on your power supply matches the one on your pedal. The great thing with most isolated power units on the market is the ability to simply grab a different cable for your powering needs. i.e. reverse polarity (like for my VMSD), batt terminal (pedals that don’t have a DC input), 3.5mm (old EHX and DOD pedals) and even cables to double up your voltage. Like say you need 18v, 21v or even 27v, you can add isolated outputs together to create the voltage you need.
One more thing to remember about isolated power is making your currents (ma) work for you. have three 9v drive pedals left to mount and only one 9v 100ma output? no problem! most of those drive units will work well in the same circuit or “loop” and they usually only require 5-15ma of draw each. Therefore, get that old daisy-chain power cord out of the closet and run all three of the drives off that single 100ma output. you will be able to power all three of the pedal and run them simultaneously since you haven’t exceeded the “current” provided from that single isolated 100ma jack.
I am sure we could talk for hours about power and how to make it work for you. I am also certain i could have missed something. So, have a question about power or anything else? hit me up - nate@rogueguitarshop.com and I will do my best to help you out! :)