I totally agree with this comment. My GSD stinks when he doesn't get totally dry. It's not yeasty, it's just strong doggy smell. We live in Florida and it's humid ;-) to say the least. He has a kiddie pool he lays in just about every day in the summer and he stays wet at the belly, hind quarters, and chest. He gets a bath every other week and then I blow off the excess water with a wet/dry vac. Put the vac hose in the exhaust port to turn it into a blower rather than a vacuum. It has some serious powerful blowing action and works well. After he's dry and I brush him out, I turn the vac back into a vacuum and he lets me vacuum him...and the floor, and the walls, and, well you can picture it.
Well there is a slight difference in us and dogs, we smell because of sweat. Dogs don't sweat through their skin, their sweat glands are on their paw pads and they regulate temperature (The reason we sweat) by panting. Though even if you towel him off well, he could still have moisture under his coat that is building up between each bath and causing bacteria and yeast to grow therefore causing the doggy smell.
As for bathing your dog regularly, I don't blame you. Sweating or not, I don't like a dirty dog and after my dog has been running around with her friends and rolling in the dirt or swimming in a pond or whatever, she is no doubt dirty. My dogs get bathed every 1-2 weeks for this reason. My dogs don't have a dog smell to them though, even if I did (and have due to situations where I couldn't bathe them) go for much much longer between baths they still don't smell. I really think you've probably got an issue with him not getting dry enough. I also wipe Gretchen down with a baby wipe a lot, she has a bad habit of rolling in stinky stuff and getting into the fish carcasses after fishing trips. x.x