Skinslapper is 100% correct--- every cymbal is slightly different. They try to get a consistent "range" of sound out of the cymbals when they make them and some manufacturers have a prototype that they try to match as a reference, but even the machine processed cymbals that are done exactly the same every time sound slightly different...
All that said, the A Custom Brilliant you refer to are generally BRIGHT and LOUD in the open position with a tight "chick" in the closed position. There are many different lines in the A Custom family, so there are some different sounds even within that category to choose from. They are made of B20 bronze--the best type of bronze for cymbals, and are pro-grade.
Here's
Zildjian's site where you can hear samples of their A Custom hi-hat reference sounds:
Zildjian.com - en-US
Hope it helps!
Good luck!