GO:0047323:   [3-methyl-2-oxobutanoate dehydrogenase (acetyl-transferring)] kinase activity
Catalysis of the reaction: ATP + 3-methyl-2-oxobutanoate dehydrogenase (acetyl-transferring) = ADP + 3-methyl-2-oxobutanoate dehydrogenase (acetyl-transferring) phosphate.