Yes, TRANSCRIBER is a Scrabble word!

Letter values in Scrabble US: T 1, R 1, A 1, N 1, S 1, C 3, R 1, I 1, B 3, E 1, R 1.

Is it a valid word?

TRANSCRIBER is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

a person who translates written messages from one language to another
someone who rewrites in a different script
someone who represents the sounds of speech in phonetic notation
someone who makes a written version of spoken material
a musician who adapts a composition for particular voices or instruments or for another style of performance