Turns up heavy metal on the radio with controversial ending in Dingle (4)
I believe the answer is:
dell
'dingle' is the definition.
('dell' can be a synonym of 'dingle')
'turns up heavy metal on the radio with controversial ending' is the wordplay.
'turns up' says the letters should be written backwards.
'heavy metal' becomes 'lead' (I've seen this before).
'on the radio' shows a homophone (sound like).
'with' says to put letters next to each other.
'ending' indicates one should take the final letters.
The final letter of 'controversial' is 'l'.
'lead' is a homophone of 'led'.
'led' in reverse letter order is 'del'.
'del'+'l'='DELL'
'in' is the link.
(Other definitions for dell that I've seen before include "Farmer's place, in song" , "Dingley - - , ('Pickwick Papers')" , "Small wooded hollow or valley" , "Deep hollow or small valley" , "Small valley; computer company" .)