Bad smelling urine in neutered male

My cat was snipped 2 years ago and his urine has NEVER stopped smelling bad, and there is no UTI present. Any ideas?

Well, what smells bad to one person doesn't necessarily  smell "off" to the next.  Have you mentioned this to your Vet and have they taken a whiff?  Do they think it smells odd?  Could it actually be the litter you use?  Or perhaps what you are feeding him?  Sometimes in humans what we eat can affect the odor of our urine, so I'm guessing it could work the same in cats  

Ritz's (female) urine sometimes smells too. My vet said that the less a cat pees the more concentrated urine will smell. Ritz pees at the most twice a day, sometimes only once.
Just, FWIW.....