Oui, c'est ça. J'avais contacté Tronographic à l'époque, je te mets la réponse que j'avais eu (j'utilise la deuxième solution proposée) :
"The first thing you should try with your Voodoo Lab ISO-5 is to use the 5.5x2.5mm right angle RED barrel cable that came with your ISO-5. This cable should be reverse polarity (Rusty Box is center positive) and have a 2.5mm center diameter. Plug this cable into the 18V output of the ISO-5 and see how you like it. We have had good things from Rusty Box owners powering from 18V.
If the 18V power supply does not give you enough headroom, then purchase this cable from Voodoo Labs: PPEH24, 2.5mm Voltage Doubling Cable - 18V or 24V. Plug the two black connectors on the cable into the 18V and 12V of the ISO-5, this will give you 30V, matching the 30V Adaptor that the Rusty Box was shipped with."