I have a dog with the same problem. I put hydrogen peroxide in her ears and the stink is gone.
One of our springers has always had problems with "smelly" ears and over the years has been diagnosed on numerous occasions with ear infections etc. usually resulting in him on antibiotics and special cleaning fluids. This is despite regular cleaning of his ears. We've been told that its common in breeds where the air doesn't get to the ears very often and that occasionally clipping the ears back using a very gentle hair clip/comb or even loose band will help - enabling air to the ears. However saying this and getting your dog to comply are two different things! I think it's something that you're probably going to have to get used to, although saying that our other springer doesn't seem to have the problem. Good luck!
My mixed terrier's ears re a stinky too. It goes away for a few days after I give him a bath, but it just comes back. I'm not sure if it is an issue, but I too would like to know if it is normal. Now that I think about it, a friend of mine has a yorkie with stinky ears.