About Negative & Positive Ground Effect Pedals - DigiTech HardWire V-10 Owner's Manual

About Negative & Positive Ground Effect Pedals
Almost all DC powered effect pedals are negative ground, meaning the negative terminal
of the battery or power supply is connected to audio ground. However, there are a
few pedals out there which have the positive battery terminal and/or power connector
connected to audio ground. The important thing to remember is that you cannot
power positive and negative ground effect pedals using a common ground (i.e., by daisy
chaining their power cables). Doing so may damage the connected power supply. When
powering these two types of pedals in the same system, you must "isolate" their power
supplies.
The V-10 Power Block is an isolated power supply, meaning that the ground on each
power output jack is isolated from all others (with the exception of power outputs 5-6
and 7-8, which can be configured as "merged" rather than "isolated"). Negative and
positive ground pedals can be powered using the V-10 Power Block as long as each
resides on its own isolated V-10 power output.
11