Originally Posted by
Ian Mackenzie
Warmth equates to the 2nd harmonic distortion in the context of THD.
Class A power amps have inherently low 3rd harmonic distortion. SE class A amps exhibit tendency towards warm sound in the absence of 3rd harmonic distortion.
SS SE amps like the Pass Aleph where like that. They are very nice but not on trend in terms of contemporary hifi listening.
In contrast the Pass X series cancelled out the 2nd harmonic distortion.
Pass then added a small amount of SE bias up to a few watts in the X.5 series.
I have one of those the X250.5.
I don’t mind tubes in preamps. They can add. A certain emotional feeling. Again it’s the 2nd harmonic distortion.
A bit of 2nd harmonic goes a long way with metal diaphragms.