[Phil Allison[_4_]]

geoff wrote:




So there is no truth in the old adage that distortion products of
over-driven valves are of predominantly even order harmonics which are
pleasing to the ear, as opposed to the predominantly odd-order harmonics
that resulting from the distortion from over-driving solid-state
devices, which are considered unpleasant ?




** With sine wave drive, the vast majority of valve output stages produce mainly 3rd harmonic distortion under high power and overdrive conditions.
The symmetrical shape of the output wave guarantees this will be the case.

Transistor amps also produce mainly 3rd harmonic under the same test conditions - with perhaps a bit more 5th and 7th as overdrive is increased.

Musical sounds consist of many frequencies at the same time. so the dominant distortion is real life is **intermodulation** between these frequencies.

Which generally sounds disgusting.



..... Phil