The voltage and current requirements for the ParaEq depend on the version you have. To determine the version, see this.
For a version 7 ParaEq, 85mA of current are required, with a DC voltage between 9V and 18V, negative tip. Different voltages don't change the amount of headroom. All input voltages are regulated down to 8V and then doubled, giving you a lot of headroom!
For a version earlier than 7, the current required depend on the voltage you're supplying. Before plugging a voltage greater than 11V into a pre-version-7 ParaEq, you must change the internal DIP switches. The greater the voltage supplied, the greater the headroom. The chart below explains the current required for each input voltage, and the required dip switch settings to go along with that input voltage.
For example, say you have a power supply that outputs 15V. Looking at the chart, you'd have to ensure that it supplies at least 95mA (more than that is fine, it just have to *at least* be 95mA). You'd also have to make sure the polarity of the jack was negative tip. Then you'd set the DIP switch on the inside of the pedal to what's shown in the picture. Depending on what version of ParaEq you have, the dip switch would have toggles or switches.
|Input Voltage (DC, negative tip)||Current Required||Version 2 and 3||Version 4 - 6|
9V - 11V
|12V - 17V||95mA|
|18V - 24V||130mA|