while all urine smells, the smell shouldn't be so strong that you notice it like that. First, is your cat male and unneutered? Then getting him neutered will correct that - the urine of a sexually mature cat reeks due to all the male hormones in the system. The same thing can be true of an unspayed female cat, but to a lesser degree.
If you're cat has already been spayed/neutered, then you need to go to the vet. Concentrated, smelly urine can be a sign of an underlying health condition. Changing the scent/type of litter won't get to the cause of the real problem, it will only mask it a bit better.
Feeding a better quality food free of corn may help as well. Cats don't digest corn well (it's added to food because it's cheap, not because it's good for cats) and that can cause some digestive issues for a great number of cats.
many years of cat rescue