I jokingly started calling him "Iron Dave" during his time with Granum (1994-ish) because of his sheer endurance. I had succeeded Cary Paul at WMMO, and Dave wanted as much airtime as he could get. He would work shifts on WHTQ and WMMO back-to-back, always ready to help me out when we had a hole in the schedule.
So sorry to hear of his passing! Dave was one of the most passionate guys I ever met when it came to the music business. I had lost track of him, and find it not surprising at all he wound up on the music side of things.