Guitar effects need power to work. There are many ways to supply power to an effects pedal, such as via a daisy chain.
9 volts battery
First of all, there is the well-known 9 volt battery. That generally works fine, some fuzz pedals sound even better with a battery, especially if the battery is less than 9 volts after use for a while. Major drawbacks of using batteries are that a) they need to be replaced over time, b) the battery consumes power as soon as cables are connected to the effects pedal and c) batteries can leak over time and d) it’s bad for the environment.
Each effect pedal has its own power supply
Replacing batteries in particular is a reason for many people to look for other options. The first option is to give each pedal its own adapter and connect these individual adapters to different sockets. With a small number of effects this is still possible (if you ‘perform’ alone at home), but it is not recommended on stage. First of all you need a lot of sockets with which you introduce the risk of ground hum. In addition, there are many and often small wires on the stage that you can easily break and it doesn’t look very neat either.
Using a daisy chain
The second option is to use a daisy chain to power your effects pedals. With a daisy chain you can connect multiple pedals to the same output of the power supply. You must use a power supply that has enough current (expressed in milliamperes – mA) to power all the pedals. In addition, you need a special daisy chain cable in which the different plugs are looped through. This way you only need one socket, which means less cables on the floor, you need less space, and it is also a cheap solution. A quick calculation shows that an adapter costs about 14 euros and a daisy chain cable with 8 outputs costs 8 euros. That is 22 euros and compared to a good multi power supply, which quickly costs 75 euros, quite a difference.
Important disadvantages of a daisy chain
However, there are also important disadvantages to a daisy chain. First of all, you can only connect pedals that require the same voltage. If there is a pedal in between that requires, for example, 18 volts, you cannot use a daisy chain. Another major drawback is that you connect all the electronics of your pedals together and very often you introduce unwanted hum due to ground loops. This especially occurs if you use both analog and digital pedals, for example if you only use simple overdrive pedals are usually fine.
Mission Engineering: Isolated versus daisy chain power supplies
One of the causes of a ground loop is that the ground of pedals is never exactly 0 volts, but a few millivolts. By linking effect pedals together, you add these small voltages together and a larger voltage is created. This causes a current to flow, which can be heard in your audio signal. This is often a 50Hz hum or a derivative thereof (100Hz, 200Hz, 400Hz etc.). You can easily remove this ground loop by using an isolated multi-power supply or battery-powering all pedals.
Daisy chain is not always recommended
In short, a daisy chain is not recommended in all cases. It’s a relatively inexpensive way to try it out at home. However, it is not recommended for use on stage. There is simply too much that can go wrong. A isolated multi-power supply may be more expensive than a daisy chain solution, but it is also a lot more reliable, causes fewer problems and is often more stable.
