Do Harbeth speakers really need a 4000 damping factor?

I tried my 30.1's with an A21, a Class D Audio SDS 470C, and ARC 150SE - but they sounded best with my Hegel H590 - greater clarity and detail resolution.  May have been my imagination... but... that's how it seemed to me.

Maybe I’m wrong, but I believe that Dampening factors have very little to do with what brand of speakers you own.

Damping factor is an amplifier measurement.  It is 8 divided by the output impedance of the amp.  Almost all solid state amps have an output impedance so low that the resulting damping factor is WAY in excess of anything meaningful as to the sound; it is largely an irrelevant specification.  The exception is tube amps which tend to have a much higher output impedance, and therefore, a lower damping factor.  There are some amps with output impedance of 2 ohms or so, for a damping factor of 4.  These amps tend to work best with speakers with high and flat impedance curves; with lower impedance speakers, the frequency response will be affected.  Tube amp manufacturers cannot easily reduce output impedance to increase damping factor, anything done for this purpose, such as increasing the turn ratio of the output transformer, will compromise the sound.  That is why speaker matching to some tube amps can be trickier.  

PrimaLuna's EVO 400 power amp has a damping factor of 7.  It's their most powerful pure tube amp ever.

The Crown Studio Reference II has a factor of >20,000.