I totally agree with Skywave regarding the transistor. And anyway the ‘A’ parts are a higher spec part than the ‘B’ grade so usually you can always sub in an ‘A’ part for a ‘B’ or ‘C’.
I too was wondering what IC he is talking about. It helps to be as specific as possible when asking for help.
And, yes, again, I would never touch any trimmers or adjustments inside the processing chains of something like a dbx noise reduction unit unless I had the definitive calibration instructions and equipment to execute them. “Calibrating” a dynamics or noise reduction unit is not like simple level set calibration…yes there is that to do too at the input and output stages of the unit, but calibrating the dynamics processors, as mentioned earlier by Skywave, typically requires a pulse generator and a good oscilloscope among other bits of test gear…and the knowledge and expertise to use them.