Hard hearted old operators making stimulants (8)

I believe the answer is:

arousers

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'stimulants' is the definition.
I know nothing about this answer so I cannot tell whether this works.

'hard hearted old operators' is the wordplay.
'hearted' indicates the central letters.
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'operators' becomes 'users' (I've seen this in another clue).
The middle letters of 'hard' are 'ar'.
'ar'+'o'+'users'='AROUSERS'

'making' acts as a link.

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I've seen this clue in The Irish Times.

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