An oldie from Cliff:
Cliff, 2008 HRI: IMHO, the essence of "chime" is plenty of high-frequency boost and a decent amount of nonlinearity. Now, by non-linearity I don't mean clipping but a transfer function that deviates significantly from a straight line. Power amps with no negative feedback are inherently less linear and that's why they sound chimier. The nonlinearity adds overtones which makes the notes sound more bell-like. The other effect of no negative feedback is increased treble as the impedance curve of the speaker imparts a treble boost due to the coil inductance.