70’s Dobros The Dopyeras transformed the resonator upside-down and customized the V. If John Dopyera stormed away from the National store in January 1929, his own resignation stemmed from more than a spur-of-the-moment tantrum. For days, the creator with the resonator fender guitar invested his own days and breaks cooperating with his own brother, Rudy, on a secret cast – a single-cone electric guitar the two considered more advanced than