Odd smell on the nose

[Seabeevet35]

I have made 3 different brews of the last year and after putting them on the keg they all smell bad. Taste is fine. But the smell is bad. Not overpoweringly awful just does not smell like a good beer. Only similarity to them is they are all light beers. One was an extract version of Blue Moon done about 8 months ago, the other two are AG kits from AHS and were just recently put on keg. Two of them used Hallertaur hops the other used Cascade and Willamette. I sanitized the system prior to kegging with PBW and cleaned out the lines. Then sanitized the kegs with StarSan as well. I also thoroughly rinsed it out. Color on the beer is pale w a very slight haze on two of them the third is crystal clear. The best way to describe the smell is a weed like dirt smell. Again its not strong or overpowering but it definitely makes the wife refuse to drink them. All three beers were brewed in early fall to early summer. Temps for fermentation are unknown as I had them in a brew bag and tried to maintain around 66 but due to overtime at work there were periods where the ice had melted long before I could replace it. Any Ideas?

 

[Quetzolcotl]

I'd replace the o-rings for your keg and check the beer lines. You can always bottle a few beers at the time of kegging to see if there is a difference later on.