A major cause of audible, non-linear distortions in capacitors
By Menno ven der Veen: “We have discovered a major cause of nonlinear distortion in capacitors and we have shown that this effect can create significant -and thus audible- distortions in sound signals…this effect can introduce high levels of intermodulation distortion and thus lead to audible differences between capacitors.” This research directly relates to output stage bias schemes.
http://milbert.com/articles#menno_capacitors