Sounds fishy, bit it's a hi-fi component (5)

I believe the answer is:

tuner

I'm a little stuck... Click here to teach me more about this clue!

'hi-fi component' is the definition.
(I've seen this in another clue)

I don't understand how the rest of the clue works.

Can you help me to learn more?

(Other definitions for tuner that I've seen before include "Radio adjuster" , "Piano adjuster" , "piano man?" , "Radio receiver" , "Adjuster of pianos" .)

I've seen this clue in the Evening Standard.

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