Back in the bad old pioneer days of high fidelity, the 1960s and early 1970s, amplifier manufacturers embarked on a specifications war, claiming ever lower percentages of total harmonic distortion. But, as J. Gordon Holt presciently
pointed out in the 1960s, without reference to the spectrum of the distortion harmonics, the actual percentage was not in itself a reliable indicator of an amplifier's sound quality. And as those early low-THD models had distortion spectra that were heavily biased toward the sonically objectionable fifth, seventh, and ninth harmonics, and suffered from other related ills, they tended to sound quite nasty.
Continue Reading »