A daisy chain is a fantastic option for home players or if you’re just after a quick fix to power multiple pedals however isn’t always the best option for your pedals.
The reason for this is quite simple. A single 9v psu can only supply a maximum amount of current. Even if you expand the outputs by using a daisy chain, you won’t be increasing the current output. This means that if your psu was kicking out 500ma from a single connector, when you add a daisy chain, it’ll still only send out a maximum of 500ma but that’ll be distributed by 5 new outputs.
If your pedals require more juice than what you’re giving them from the power supply you can cause noise issues because the outputs aren’t isolated and you’re not providing the pedals with the right power required for them to work.
This is when having a power brick with isolated outputs becomes very important because you can provide each pedal on your board with a healthy supply of current – enough for them to work as intended by the pedal designers.
Note: You should always ensure that you know what supply your pedals need and that you connect them to a supply that provides ample current! So, if your pedal requirements are 9v DC 200mA then you should ensure that’s what the supply will give. It doesn’t matter if the power supply provides more current than the pedal requires but should never be less.