@ahal1 "Do Harbeth speakers really need a 4000 damping factor?” no!
even “ideal DF” amp w/ 1000000 damping factor cannot deliver it to the drivers, due to drivers resistance and speaker x-over design.. typical coil in low-freq. driver circuit has ~ 200mOhms of resistance, which limits damping factor at 30 level, for 6 Ohms spkr, assuming amp’s damping factor is infinite!