High Quality Content by WIKIPEDIA articles! Dumble musical instrument amplifiers are custom manufactured in very limited numbers by Alexander "Howard" Dumble of Los Angeles, California. Dumble began making amplifiers in the late 1960s in Santa Cruz. There are reportedly fewer than 300 in total. Amplifier models have included the Overdrive Special (ODS), Overdrive Reverb, Steel String Singer (SSS), Dumbleland, Phoenix (a rack mounted amp), Hotel Hog and Winterland. Dumble amplifiers are considered to be one of the few precursors to the explosion of Boutique amplifier companies on the market.