I remember that. I think the voice actor for Darkseid was the same guy who played the villain (Mad Cat?) in Inspector Gadget IIRC.
That was Frank Welker, who's also played probably thousands of other characters, including Fred on Scooby-Doo
and Megatron on Transformers
. But yes, his Darkseid voice and his Dr. Claw voice were the same. I believe he played both Darkseid and Kalibak, and no doubt others.