A telephone that is right for a studio (7)
I believe the answer is:
atelier
'studio' is the definition.
(atelier is a kind of studio)
'a telephone that is right' is the wordplay.
'telephone' becomes 'tel' (short for telephone).
'that is' becomes 'ie' (short for Latin 'id est', 'that is').
'right' becomes 'r' (common abbreviation).
'a'+'tel'+'ie'+'r'='ATELIER'
'for a' acts as a link.
(Other definitions for atelier that I've seen before include "Tie earl up in the artist's place" , "I relate to workshop used by artist" , "room for artist" , "Artist's workshop, studio" , "Designer's workshop" .)