Aspen Pittman, founder of Groove Tubes and author of The Tube Amp Book, died last weekend in a car crash in Southern California. Pittman spent the '60s working at the first Guitar Center. In 1979, he founded Groove Tubes and revolutionized tube amps. He made an even bigger mark on the guitar world with The Tube Amp Book. Amp builders have used the book for years.
For more information on Pittman's legacy and to read tributes, please see the Guitar.com article.
Watch this tribute below from Pittman's close friend, Norman Harris, owner of Norman's Rare Guitars: