Compare quality of TV control (8)
I believe the answer is:
contrast
'compare' is the definition.
(I've seen this before)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for contrast that I've seen before include "Compare to show differences" , "Distinction" , "State of being strikingly different" , "Unlikeness shown by comparison" , "Something completely different" .)