D'après la FAQ, je dirais 800 mA, ce qui fait pas mal...
Citation:
The power supply is large, yes. To ensure the same signal integrity of its bigger brothers, we needed a burly power supply.
That said, these two seem to work just fine:
Strymon Zuma R300—Appears to work fine when doubling up TWO 9V outputs
Voodoo Lab Pedal Power 4x4—Appears to work fine when doubling up TWO 9V outputs
IMPORTANT NOTE #1: HX Stomp’s sophisticated circuitry pulls notably more than your average pedal. Hence, we used a DC IN jack with a larger center pin to sort of disincentivize people from throwing whatever at it. The stock DC cables that come with the power supplies listed above will NOT fit. Note that Eventide does the exact same thing with their H9.
IMPORTANT NOTE #2: YOU ARE ON YOUR OWN. Feel free to use this FAQ as a starting point, but Line 6 is not responsible for any damage incurred when using HX Stomp with any third-party power supplies. That is, if someone writes "B-b-but Line 6 said I could use [power supply X!]," someone will hopefully refer them to this post where I make it perfectly clear that we only *officially* support our DC-3G.
