Neighbours of Calton Road club Studio 24 wanted its licence removed following a number of complaints.
However, the city's licensing board stopped short of suspending its licence after saying that action had been taken by the club to reduce noise.
Noise levels have been fixed at a level agreed with noise team officers, with the controls being kept in a locked cupboard.
When issuing the written warning, licensing leader Marjorie Thomas said she was "happy" with recent progress and actions taken by management. However, she added: "If this is brought to us again we will take stronger action."
Afterwards, Matthew Maguire, a sound engineer for the club, said: "We've always done everything we could. The fact we have got a yellow card is a scary scenario but the levels have not been touched. We've got a scary scenario with us and a neighbour and I've got no doubt he will complain again."