Oral History Information
Andy Marshall has had a deep and rich musical education both in the classroom and on stage. In 1986 he established THD Electronics to focus on manufacturing guitar amplifiers. He set out to provide reissue amps (the A-10 was first), which really had not been done before and it gave Andy a chance to demonstrate the advantages of tube amplification to younger musicians. A string of innovations followed such as the UniValve (which had no cabinet, just a metal cage - and this product helped launch the Lunch Box Amp craze), the Plexi amp (later renamed the Type-O after some slight circuit board enhancements), and the Hot Plate power attenuator (a volume control for tube amps), as well as several other products over the years. Andy closed the business in 2011 to focus on design work and consulting as well as returning to repair work, which he thoroughly enjoys.