My lagers always contain a lot of sulfur (like garbage or rotting vegetation) aromas. My boils are typically 75 minutes, full rolling boils uncovered with overhead vent fan using gas plus electric heat stick augmentation. I use both liquid yeast with stirred starters and dry yeast (all style-appropriate lager yeasts), all scaled to appropriate pitching rates using the calculator at mrmalty.com. Typically I chill to 50 °F (10 °C) and pitch. Then I ferment around 52 °F (11°C) in a dedicated ferment chamber with external temperature control, proxy thermo-well in a separate jug of water, and forced air convection until fermentation slows, and a sample shows about 65-75% complete. Then I raise the temperature over a couple days to about 65 °F (18 °C) and let it sit for a while. I have read a warmer fermentation at the end helps scrub sulfur and absorb diacetyl. My diacetyl is getting cleaned up, but not the sulfur.
The Wiz shares some tips for scrubbing sulfur smells out of lagers and preparing an oak barrel for beer aging.