Who voices the phonebox operator?

[Slime Drips]

Dude sounds like 90s American cartoon Dr Robotnik, and I know that actor passed away a long time ago, so I'm extremely curious who this person is who is doing the perfect gruff eggman.

None of the online credits listings list who played what character, so I'm at a loss.

Edit: I'm referring to Long John Baldry. I was not aware the other early Sonic cartoon had Jim Cummings as Robotnik. The operator sounds a lot like John.

[Mobile Suit God Damn]

It's obviously Davros, mate.