Branch out, using hard drive provided with playback (6)
I believe the answer is:
ramify
'branch out' is the definition.
(I've seen this before)
'hard drive provided with playback' is the wordplay.
'hard drive' becomes 'ram' (ram is memory (similar to hard drive)).
'provided' becomes 'if'.
'with' is a charade indicator (letters next to each other).
'playback' becomes 'y' (the back of play is y).
'ram'+'if'+'y'='RAMIFY'
'using' is the link.
(Other definitions for ramify that I've seen before include "Divide into branches" , "Branch - spread out" , "Split into branches" , "Produce branches" .)