I would expect it is not very high output impedance / current output driven, though it may have a relatively low damping factor and may have some current feedback. The issue is most speakers today are designed for an amplifier with high damping factor / low output impedance. Too high of output impedance and your bass response changes, and you screw up the cross-over points.
All that is what I hear with Bakoon amplifiers.Which are class A/B but which are reputed to be zero negative feedback/high output impedance/ current drive/probably low damping factor amplifiers.In simple terms they simply sound incredibly clear and pure.Which I have really only heard elsewhere from expensive SET amps like the