Yes, that's what Power Converters do...
It's more efficient than magma crucible to geothermal or thermal generator, at nearly a 2:5 ratio. 1800 MJ : 4375 EU or 1:2.43, to be exact.
I should also point out that Power Converters have been around (in a different form) far longer than Magma Crucibles- since at least Minecraft 1.2.5. The old Power Converters only worked with EU and MJ, used the 2:5 ratio, included one block for each different conversion, and included the Oil and Lava Fabricators that the mod author has since moved into another mod of his, Minefactory Reloaded.