Koji Uenichi played both Spectreman and Ra/Karras.
In the Brazilian dub, Carlos Seidl voiced Gori and was the narrator (using a deep intonation for the former and a high-pitch voice for the latter).
Foreign Dub as Basis: The Brazilian dub is based on the American dub, including the Opening Narration. Ra is named Karas, similar to his English name Karras, while Nebula is named Dominantes ("Dominant Ones"), thematically close (although not a literal translation) to the English name Overlords. This happens because the Brazilian TV channel to first air the show imported it from the USA instead of buying it directly from Japan.
Uncredited Role: the English Dub does not credit any of the voice actors, though it's commonly assumed that Mel Welles (the dub director and writer) voiced Karras and the Overlords (and most other characters), Charles Howerton serves as the Opening Narration, and Corey Burton played George.
What Could Have Been: Evidenceexists of a planned Spectreman sequel series to have been released in the 90s called Shin Spectreman. The plot would've been that the Overlords secretly resurrect Gori as they regreted the loss of his genius mind, but he would escape their security and try and take over Earth again. So the original Spectreman (now called Spectreman First) sends three new Spectremen named Ray, Sunny, & Cima to stop him.
U.S. version: The English-dubbed adaptation of Spectreman was produced and aired in the U.S. in 1978, a full 7 years after the original Japanese version. (Compare to the two years it took for Mighty Morphin' Power Rangers to be created from Zyuranger.) As such, the dubbed Spectreman has multiple unintentional anachronisms where early Seventies cars, hair, and fashion stand out. This adaptation featured a brand new "Spectreman" opening theme song with prominent use of synthesizer, which would not have been TV theme instrumentation in 1971. Also, to contemporary audiences of 1978 the costumed Spectreman would have somewhat resembled a lame knock-off of C-3PO from Star Wars, a 1977 release.
The song in the U.S. opening used the backing track of the song "The First day of Forever", from the Mystic Moods Orchestra's 1973 album Awakening, along with a new lyrics.
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