Pretty much the same voice, although in TFTM it was less electronically warbled after for Galvatron, but then in the TV series it was warbled and pretty much sounded like Megatron. Or more accurately, the voice was exactly the same as Megatron first in the TV series and then later "unwarbled" for TFTM (I keep forgetting that TFTM only came out in Japan in 1988).