I own Harbeth 30.1's driven by a pair of Rogue Audio M-180 monoblocks (180wpc) with KT120 output tubes. After years of experimenting I have found my sweet spot.
As far as using the 4 or 8 ohm taps, I was told to try both and use the ones that sound better. Without getting too deep in the weeds, for me it was the 8 ohm taps and that's what I use.
As far as using the 4 or 8 ohm taps, I was told to try both and use the ones that sound better. Without getting too deep in the weeds, for me it was the 8 ohm taps and that's what I use.